ChemWiki - User contributions [en]

It:dichlorodifluromethane

2006-12-08T13:59:13Z

Dh405:

{| border="1" cellpadding="3" cellspacing="0" style="float: right; clear: right; margin: 0 0 2em 2em;"
|-
! colspan="2" style="background:#efefef;" | Dichlorodifluoromethane
|-
! style="background:#ffdead;" | 2D Structure
! style="background:#ffdead;" | 3D Structure
|-
| [[Image:Dichlorodifluoromethane | 2D Structure ]]
|<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 150; cpk 25%;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>water.mol
HEADER NONAME 06-Dec-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 06-Dec-06 0 NONE 4
ATOM 1 Cl 0 -1.472 0.684 -0.000 0.00 0.00 Cl+0
ATOM 2 C 0 -0.000 -0.357 0.000 0.00 0.00 C+0
ATOM 3 Cl 0 1.472 0.684 -0.000 0.00 0.00 Cl+0
ATOM 4 F 0 0.000 -1.164 1.142 0.00 0.00 F+0
ATOM 5 F 0 -0.000 -1.164 -1.142 0.00 0.00 F+0
CONECT 1 2 0 0 0 NONE 10
CONECT 2 1 3 4 5 NONE 11
CONECT 3 2 0 0 0 NONE 12
CONECT 4 2 0 0 0 NONE 13
CONECT 5 2 0 0 0 NONE 14
END NONE 15
M END</inlineContents>
</jmolApplet>
</jmol>

|- align="left"
! style="background:#ffdead;" | Chemical Name
| dichloro-difluoro-methane

|- align="left"
! style="background:#ffdead;" |Formula
| CCl2F2

|- align="left"
! style="background:#ffdead;" |Synonyms
| Fluorocarbon 12, Refrigerant 12, Freon 12,
Propellant 12, Halon 122, FC 12, Freon F-12.

|- align="left"
! style="background:#ffdead;" |CAS No.
| [75-71-8]

|- align="left"
! style="background:#ffdead;" |Beilstein No.
| 1732393

|-
! colspan="2" style="background:#efefef;" | Properties

|- align="left"
! style="background:#ffdead;" |Type of Substance
| Acyclic

|- align="left"
! style="background:#ffdead;" |Boiling Point
| -29.8°C / -21.6°F

|- align="left"
! style="background:#ffdead;" |Melting Point
| -157.7°C / -252°F

|- align="left"
! style="background:#ffdead;" |Density
| 1.293

|- align="left"
! style="background:#ffdead;" |Solubility
| Nearly insoluble in water;
solubale in most organic solvents.
|}

==Introduction==

Dichlorodifluoromethane is a colorless, nonflammable gas with almost no odor (ether-like odor at extremely high concentrations).It is used as a refrigerant gas, an aerosol propellant, in plastics, and as a leak detecting agent until its manufacture was discontinued in 1995, due to concerns about damage to the ozone layer. The ozone depletion potential of R-12 is 0.82, which is relatively high.

==History==

The Major use of dichlorodifluoromethane is as a refrigerant gas. Refrigerants like sulfur dioxide and methyl chloride (used in early days when refrigerators were invented) were causing people to die. Ammonia had an equally serious toxic effect if it leaked. Refrigeration engineers searched for acceptable substitutes until the 1920s, when a number of synthetic refrigerants called halocarbons or CFCs (chlorofluorocarbons) were developed by Frigidaire. The best known of these substances was patented under the brand name of Freon. Chemically, Freon was created by the substitution of two chlorine and two fluorine atoms for the four hydrogen atoms in methane (CH4); the result, dichlorodifluoromethane (CCl2F2), is odourless and is toxic only in extremely large doses.

==Synthesis of Dichlorodifluoromethane==

Laboratory:

CCl4 + HF → CFCl3 + CCl2F2 + HCl (Catalyst: SbF3Cl2)

Industry:

HF(g) + CCl4 → CCl3F + CCl2F2 + CClF3 (Carbon catalyst)

==Spectrums of Dichlorodifluoromethane==

[[Image:F-12-IR.JPG | IR Spectrum]]

[[Image:F-12-Mas.JPG | Mass Spectrum]]

==Hazard==

* Dichlorodifluoromethane can affect you when breathed in.

* Contact with the liquid can cause cracking anf drying of the skin, and may cause frostbite.

* Dichlorodifluoromethane can cause eye irritation and severe eye pain.

* Breathing the gas can irritate the mouth, nose and throat.

* Exposure to high concentrations of the gas can cause the heart to beat irregularly or to stop. This can cause death.

* Exposure can cause dizziness, light-headedness, and trouble with concentration.

==Reference==

1. http://webbook.nist.gov/cgi/cbook.cgi?ID=75-71-8&Type=IR-SPEC&Index=QUANT-IR,0#IR-SPEC

2. http://webbook.nist.gov/cgi/cbook.cgi?ID=C75718&Mask=200#Mass-Spec

3. http://www.wou.edu/~avorder/Refrigeration.htm

It:dichlorodifluromethane

2006-12-08T13:58:28Z

Dh405:

It:dichlorodifluromethane

2006-12-08T00:20:55Z

Dh405:

{| border="1" cellpadding="3" cellspacing="0" style="float: right; clear: right; margin: 0 0 2em 2em;"
|-
! colspan="2" style="background:#efefef;" | Dichlorodifluoromethane
|-
! style="background:#ffdead;" | 2D Structure
! style="background:#ffdead;" | 3D Structure
|-
| [[Image:Dichlorodifluoromethane | 2D Structure ]]
|<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 150; cpk 25%;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>water.mol
HEADER NONAME 06-Dec-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 06-Dec-06 0 NONE 4
ATOM 1 Cl 0 -1.472 0.684 -0.000 0.00 0.00 Cl+0
ATOM 2 C 0 -0.000 -0.357 0.000 0.00 0.00 C+0
ATOM 3 Cl 0 1.472 0.684 -0.000 0.00 0.00 Cl+0
ATOM 4 F 0 0.000 -1.164 1.142 0.00 0.00 F+0
ATOM 5 F 0 -0.000 -1.164 -1.142 0.00 0.00 F+0
CONECT 1 2 0 0 0 NONE 10
CONECT 2 1 3 4 5 NONE 11
CONECT 3 2 0 0 0 NONE 12
CONECT 4 2 0 0 0 NONE 13
CONECT 5 2 0 0 0 NONE 14
END NONE 15
M END</inlineContents>
</jmolApplet>
</jmol>

|- align="left"
! style="background:#ffdead;" | Chemical Name
| dichloro-difluoro-methane

|- align="left"
! style="background:#ffdead;" |Formula
| CCl2F2

|- align="left"
! style="background:#ffdead;" |Synonyms
| Fluorocarbon 12, Refrigerant 12, Freon 12,
Propellant 12, Halon 122, FC 12, Freon F-12.

|- align="left"
! style="background:#ffdead;" |CAS No.
| [75-71-8]

|- align="left"
! style="background:#ffdead;" |Beilstein No.
| 1732393

|-
! colspan="2" style="background:#efefef;" | Properties

|- align="left"
! style="background:#ffdead;" |Type of Substance
| Acyclic

|- align="left"
! style="background:#ffdead;" |Boiling Point
| -29.8°C / -21.6°F

|- align="left"
! style="background:#ffdead;" |Melting Point
| -157.7°C / -252°F

|- align="left"
! style="background:#ffdead;" |Density
| 1.293

|- align="left"
! style="background:#ffdead;" |Solubility
| Nearly insoluble in water;
solubale in most organic solvents.
|}

==Introduction==

Dichlorodifluoromethane is a colorless, nonflammable gas with almost no odor (ether-like odor at extremely high concentrations).It is used as a refrigerant gas, an aerosol propellant, in plastics, and as a leak detecting agent until its manufacture was discontinued in 1995, due to concerns about damage to the ozone layer. The ozone depletion potential of R-12 is 0.82, which is relatively high.

==History==

The Major use of dichlorodifluoromethane is as a refrigerant gas. Refrigerants like sulfur dioxide and methyl chloride (used in early days when refrigerators were invented) were causing people to die. Ammonia had an equally serious toxic effect if it leaked. Refrigeration engineers searched for acceptable substitutes until the 1920s, when a number of synthetic refrigerants called halocarbons or CFCs (chlorofluorocarbons) were developed by Frigidaire. The best known of these substances was patented under the brand name of Freon. Chemically, Freon was created by the substitution of two chlorine and two fluorine atoms for the four hydrogen atoms in methane (CH4); the result, dichlorodifluoromethane (CCl2F2), is odourless and is toxic only in extremely large doses.

==Synthesis of Dichlorodifluoromethane==

Laboratory:

CCl4 + HF → CFCl3 + CCl2F2 + HCl (Catalyst: SbF3Cl2)

Industry:

HF(g) + CCl4 → CCl3F + CCl2F2 + CClF3 (Carbon catalyst)

==Spectrums of Dichlorodifluoromethane==

[[Image:F-12-IR.JPG | IR Spectrum]]

[[Image:F-12-Mas.JPG | Mass Spectrum]]

==Reference==

1. http://webbook.nist.gov/cgi/cbook.cgi?ID=75-71-8&Type=IR-SPEC&Index=QUANT-IR,0#IR-SPEC

2. http://webbook.nist.gov/cgi/cbook.cgi?ID=C75718&Mask=200#Mass-Spec

3. http://www.wou.edu/~avorder/Refrigeration.htm

It:dichlorodifluromethane

2006-12-08T00:19:17Z

Dh405:

{| border="1" cellpadding="3" cellspacing="0" style="float: right; clear: right; margin: 0 0 2em 2em;"
|-
! colspan="2" style="background:#efefef;" | Dichlorodifluoromethane
|-
! style="background:#ffdead;" | 2D Structure
! style="background:#ffdead;" | 3D Structure
|-
| [[Image:Dichlorodifluoromethane | 2D Structure ]]
|<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 150; cpk 25%;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>water.mol
HEADER NONAME 06-Dec-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 06-Dec-06 0 NONE 4
ATOM 1 Cl 0 -1.472 0.684 -0.000 0.00 0.00 Cl+0
ATOM 2 C 0 -0.000 -0.357 0.000 0.00 0.00 C+0
ATOM 3 Cl 0 1.472 0.684 -0.000 0.00 0.00 Cl+0
ATOM 4 F 0 0.000 -1.164 1.142 0.00 0.00 F+0
ATOM 5 F 0 -0.000 -1.164 -1.142 0.00 0.00 F+0
CONECT 1 2 0 0 0 NONE 10
CONECT 2 1 3 4 5 NONE 11
CONECT 3 2 0 0 0 NONE 12
CONECT 4 2 0 0 0 NONE 13
CONECT 5 2 0 0 0 NONE 14
END NONE 15
M END</inlineContents>
</jmolApplet>
</jmol>

|- align="left"
! style="background:#ffdead;" | Chemical Name
| dichloro-difluoro-methane

|- align="left"
! style="background:#ffdead;" |Formula
| CCl2F2

|- align="left"
! style="background:#ffdead;" |Synonyms
| Fluorocarbon 12, Refrigerant 12, Freon 12,
Propellant 12, Halon 122, FC 12, Freon F-12.

|- align="left"
! style="background:#ffdead;" |CAS No.
| [75-71-8]

|- align="left"
! style="background:#ffdead;" |Beilstein No.
| 1732393

|-
! colspan="2" style="background:#efefef;" | Properties

|- align="left"
! style="background:#ffdead;" |Type of Substance
| Acyclic

|- align="left"
! style="background:#ffdead;" |Boiling Point
| -29.8°C / -21.6°F

|- align="left"
! style="background:#ffdead;" |Melting Point
| -157.7°C / -252°F

|- align="left"
! style="background:#ffdead;" |Density
| 1.293

|- align="left"
! style="background:#ffdead;" |Solubility
| Nearly insoluble in water;
solubale in most organic solvents.
|}

==Introduction==

Dichlorodifluoromethane is a colorless, nonflammable gas with almost no odor (ether-like odor at extremely high concentrations).It is used as a refrigerant gas, an aerosol propellant, in plastics, and as a leak detecting agent until its manufacture was discontinued in 1995, due to concerns about damage to the ozone layer. The ozone depletion potential of R-12 is 0.82, which is relatively high.

==History==

The Major use of dichlorodifluoromethane is as a refrigerant gas. Refrigerants like sulfur dioxide and methyl chloride (used in early days when refrigerators were invented) were causing people to die. Ammonia had an equally serious toxic effect if it leaked. Refrigeration engineers searched for acceptable substitutes until the 1920s, when a number of synthetic refrigerants called halocarbons or CFCs (chlorofluorocarbons) were developed by Frigidaire. The best known of these substances was patented under the brand name of Freon. Chemically, Freon was created by the substitution of two chlorine and two fluorine atoms for the four hydrogen atoms in methane (CH4); the result, dichlorodifluoromethane (CCl2F2), is odourless and is toxic only in extremely large doses.

==Synthesis of Dichlorodifluoromethane==

Laboratory:

CCl4 + HF → CFCl3 + CCl2F2 + HCl (Catalyst: SbF3Cl2)

Industry:

HF(g) + CCl4 → CCl3F + CCl2F2 + CClF3 (Carbon catalyst)

==Spectrums of Dichlorodifluoromethane==

[[Image:F-12-IR.JPG | IR Spectrum]]

[[Image:F-12-Mas.JPG | Mass Spectrum]]

==Reference==

1. http://webbook.nist.gov/

2. http://www.wou.edu/~avorder/Refrigeration.htm

It:dichlorodifluromethane

2006-12-08T00:06:21Z

Dh405: /* Reference */

It:dichlorodifluromethane

2006-12-08T00:05:07Z

Dh405: /* Spectrums of Dichlorodifluoromethane */

It:dichlorodifluromethane

2006-12-08T00:02:31Z

Dh405:

It:dichlorodifluromethane

2006-12-08T00:01:52Z

Dh405: /* Introduction */

It:dichlorodifluromethane

2006-12-07T23:53:46Z

Dh405:

It:dichlorodifluromethane

2006-12-07T23:53:36Z

Dh405:

It:dichlorodifluromethane

2006-12-07T23:50:34Z

Dh405:

File:F-12-Mas.JPG

2006-12-07T23:41:00Z

Dh405: by Tina Han

by Tina Han

File:F-12-IR.JPG

2006-12-07T23:40:47Z

Dh405: by Tina Han

by Tina Han

It:dichlorodifluromethane

2006-12-07T23:27:33Z

Dh405:

It:dichlorodifluromethane

2006-12-07T23:07:36Z

Dh405:

{| border="1" cellpadding="3" cellspacing="0" style="float: right; clear: right; margin: 0 0 1em 1em;"
|-
! colspan="2" style="background:#efefef;" | Dichlorodifluoromethane
|-
! style="background:#ffdead;" | 2D Structure
! style="background:#ffdead;" | 3D Structure
|-
| [[Image:Dichlorodifluoromethane | 2D Structure ]]
|<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 150; cpk 25%;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>water.mol
HEADER NONAME 06-Dec-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 06-Dec-06 0 NONE 4
ATOM 1 Cl 0 -1.472 0.684 -0.000 0.00 0.00 Cl+0
ATOM 2 C 0 -0.000 -0.357 0.000 0.00 0.00 C+0
ATOM 3 Cl 0 1.472 0.684 -0.000 0.00 0.00 Cl+0
ATOM 4 F 0 0.000 -1.164 1.142 0.00 0.00 F+0
ATOM 5 F 0 -0.000 -1.164 -1.142 0.00 0.00 F+0
CONECT 1 2 0 0 0 NONE 10
CONECT 2 1 3 4 5 NONE 11
CONECT 3 2 0 0 0 NONE 12
CONECT 4 2 0 0 0 NONE 13
CONECT 5 2 0 0 0 NONE 14
END NONE 15
M END</inlineContents>
</jmolApplet>
</jmol>

|- align="left"
! style="background:#ffdead;" | Chemical Name
| dichloro-difluoro-methane

|- align="left"
! style="background:#ffdead;" |Formula
| CCl2F2

|- align="left"
! style="background:#ffdead;" |Synonyms
| Fluorocarbon 12, Refrigerant 12, Freon 12,
Propellant 12, Halon 122, FC 12, Freon F-12.

|- align="left"
! style="background:#ffdead;" |CAS No.
| [75-71-8]

|- align="left"
! style="background:#ffdead;" |Beilstein No.
| 1732393

|-
! colspan="2" style="background:#efefef;" | Properties

|- align="left"
! style="background:#ffdead;" |Type of Substance
| Acyclic

|- align="left"
! style="background:#ffdead;" |Boiling Point
| -29.8°C / -21.6°F

|- align="left"
! style="background:#ffdead;" |Melting Point
| -157.7°C / -252°F

|- align="left"
! style="background:#ffdead;" |Density
| 1.293

|- align="left"
! style="background:#ffdead;" |Solubility
| Nearly insoluble in water;
solubale in most organic solvents.
|}

==Introduction==

Dichlorodifluoromethane is a colorless, nonflammable gas with almost no odor (ether-like odor at extremely high concentrations).It is used as a refrigerant gas, an aerosol propellant, in plastics, and as a leak detecting agent until its manufacture was discontinued in 1995, due to concerns about damage to the ozone layer. The ozone depletion potential of R-12 is 0.82, which is relatively high.

==History==

The Major use of dichlorodifluoromethane is as a refrigerant gas. Refrigerants like sulfur dioxide and methyl chloride (used in early days when refrigerators were invented) were causing people to die. Ammonia had an equally serious toxic effect if it leaked. Refrigeration engineers searched for acceptable substitutes until the 1920s, when a number of synthetic refrigerants called halocarbons or CFCs (chlorofluorocarbons) were developed by Frigidaire. The best known of these substances was patented under the brand name of Freon. Chemically, Freon was created by the substitution of two chlorine and two fluorine atoms for the four hydrogen atoms in methane (CH4); the result, dichlorodifluoromethane (CCl2F2), is odourless and is toxic only in extremely large doses.

==Synthesis of Dichlorodifluoromethane==

Laboratory:

CCl4 + HF → CFCl3 + CCl2F2 + HCl (Catalyst: SbF3Cl2)

Industry:

HF(g) + CCl4 → CCl3F + CCl2F2 + CClF3 (Carbon catalyst)

==Spectrums of Dichlorodifluoromethane==

It:dichlorodifluromethane

2006-12-07T23:03:59Z

Dh405:

{| border="1" cellpadding="3" cellspacing="0" style="float: right; clear: right;"
|-
! colspan="2" style="background:#efefef;" | Dichlorodifluoromethane
|-
! style="background:#ffdead;" | 2D Structure
! style="background:#ffdead;" | 3D Structure
|-
| [[Image:Dichlorodifluoromethane | 2D Structure ]]
|<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 150; cpk 25%;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>water.mol
HEADER NONAME 06-Dec-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 06-Dec-06 0 NONE 4
ATOM 1 Cl 0 -1.472 0.684 -0.000 0.00 0.00 Cl+0
ATOM 2 C 0 -0.000 -0.357 0.000 0.00 0.00 C+0
ATOM 3 Cl 0 1.472 0.684 -0.000 0.00 0.00 Cl+0
ATOM 4 F 0 0.000 -1.164 1.142 0.00 0.00 F+0
ATOM 5 F 0 -0.000 -1.164 -1.142 0.00 0.00 F+0
CONECT 1 2 0 0 0 NONE 10
CONECT 2 1 3 4 5 NONE 11
CONECT 3 2 0 0 0 NONE 12
CONECT 4 2 0 0 0 NONE 13
CONECT 5 2 0 0 0 NONE 14
END NONE 15
M END</inlineContents>
</jmolApplet>
</jmol>

|- align="left"
! style="background:#ffdead;" | Chemical Name
| dichloro-difluoro-methane

|- align="left"
! style="background:#ffdead;" |Formula
| CCl2F2

|- align="left"
! style="background:#ffdead;" |Synonyms
| Fluorocarbon 12, Refrigerant 12, Freon 12,
Propellant 12, Halon 122, FC 12, Freon F-12.

|- align="left"
! style="background:#ffdead;" |CAS No.
| [75-71-8]

|- align="left"
! style="background:#ffdead;" |Beilstein No.
| 1732393

|-
! colspan="2" style="background:#efefef;" | Properties

|- align="left"
! style="background:#ffdead;" |Type of Substance
| Acyclic

|- align="left"
! style="background:#ffdead;" |Boiling Point
| -29.8°C / -21.6°F

|- align="left"
! style="background:#ffdead;" |Melting Point
| -157.7°C / -252°F

|- align="left"
! style="background:#ffdead;" |Density
| 1.293

|- align="left"
! style="background:#ffdead;" |Solubility
| Nearly insoluble in water;
solubale in most organic solvents.
|}

==Introduction==

Dichlorodifluoromethane is a colorless, nonflammable gas with almost no odor (ether-like odor at extremely high concentrations).It is used as a refrigerant gas, an aerosol propellant, in plastics, and as a leak detecting agent until its manufacture was discontinued in 1995, due to concerns about damage to the ozone layer. The ozone depletion potential of R-12 is 0.82, which is relatively high.

==History==

The Major use of dichlorodifluoromethane is as a refrigerant gas. Refrigerants like sulfur dioxide and methyl chloride (used in early days when refrigerators were invented) were causing people to die. Ammonia had an equally serious toxic effect if it leaked. Refrigeration engineers searched for acceptable substitutes until the 1920s, when a number of synthetic refrigerants called halocarbons or CFCs (chlorofluorocarbons) were developed by Frigidaire. The best known of these substances was patented under the brand name of Freon. Chemically, Freon was created by the substitution of two chlorine and two fluorine atoms for the four hydrogen atoms in methane (CH4); the result, dichlorodifluoromethane (CCl2F2), is odourless and is toxic only in extremely large doses.

==Synthesis of Dichlorodifluoromethane==

Laboratory:

CCl4 + HF → CFCl3 + CCl2F2 + HCl (Catalyst: SbF3Cl2)

Industry:

HF(g) + CCl4 → CCl3F + CCl2F2 + CClF3 (Carbon catalyst)

It:dichlorodifluromethane

2006-12-07T22:19:45Z

Dh405: /* '''Dichlorodifluoromethane(CCl2F2)''' */

{| border="1" cellpadding="5" cellspacing="0" style="float: right; clear: right;"
|-
! style="background:#efefef;" | Dichlorodifluoromethane
|- align="center"
| [[Image:Dichlorodifluoromethane]]
|-
! style="background:#efefef;" | 3D Structure
|- align="center"
|<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 150; cpk 25%;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>water.mol
HEADER NONAME 06-Dec-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 06-Dec-06 0 NONE 4
ATOM 1 Cl 0 -1.472 0.684 -0.000 0.00 0.00 Cl+0
ATOM 2 C 0 -0.000 -0.357 0.000 0.00 0.00 C+0
ATOM 3 Cl 0 1.472 0.684 -0.000 0.00 0.00 Cl+0
ATOM 4 F 0 0.000 -1.164 1.142 0.00 0.00 F+0
ATOM 5 F 0 -0.000 -1.164 -1.142 0.00 0.00 F+0
CONECT 1 2 0 0 0 NONE 10
CONECT 2 1 3 4 5 NONE 11
CONECT 3 2 0 0 0 NONE 12
CONECT 4 2 0 0 0 NONE 13
CONECT 5 2 0 0 0 NONE 14
END NONE 15
M END</inlineContents>
</jmolApplet>
</jmol>

----

{| cellpadding="2" cellspacing="2" align="ceter"

|- align="left"
! style="background:#ffdead;" | Chemical Name
| dichloro-difluoro-methane

|- align="left"
! style="background:#ffdead;" |Formula
| CCl2F2

|- align="left"
! style="background:#ffdead;" |Synonyms
| Fluorocarbon 12, Refrigerant 12, Freon 12,
Propellant 12, Halon 122, FC 12, Freon F-12.

|- align="left"
! style="background:#ffdead;" |CAS No.
| [75-71-8]

|- align="left"
! style="background:#ffdead;" |Beilstein No.
| 1732393

|- align="left"
! style="background:#ffdead;" |Type of Substance
| Acyclic

|- align="left"
! style="background:#ffdead;" |Boiling Point
| -29.8°C / -21.6°F

|- align="left"
! style="background:#ffdead;" |Melting Point
| -157.7°C / -252°F

|- align="left"
! style="background:#ffdead;" |Density
| 1.293

|- align="left"
! style="background:#ffdead;" |Solubility
| Nearly insoluble in water;
solubale in most organic solvents.
|}
|}

==Introduction==

Dichlorodifluoromethane is a colorless, nonflammable gas with almost no odor (ether-like odor at extremely high concentrations).It is used as a refrigerant gas, an aerosol propellant, in plastics, and as a leak detecting agent until its manufacture was discontinued in 1995, due to concerns about damage to the ozone layer. The ozone depletion potential of R-12 is 0.82, which is relatively high.

==History==

The Major use of dichlorodifluoromethane is as a refrigerant gas. Refrigerants like sulfur dioxide and methyl chloride (used in early days when refrigerators were invented) were causing people to die. Ammonia had an equally serious toxic effect if it leaked. Refrigeration engineers searched for acceptable substitutes until the 1920s, when a number of synthetic refrigerants called halocarbons or CFCs (chlorofluorocarbons) were developed by Frigidaire. The best known of these substances was patented under the brand name of Freon. Chemically, Freon was created by the substitution of two chlorine and two fluorine atoms for the four hydrogen atoms in methane (CH4); the result, dichlorodifluoromethane (CCl2F2), is odourless and is toxic only in extremely large doses.

It:dichlorodifluromethane

2006-12-06T19:06:09Z

Dh405: /* '''Dichlorodifluoromethane(CCl2F2)''' */

=='''Dichlorodifluoromethane(CCl2F2)'''==
{| border="1" cellpadding="5" cellspacing="0" align="center"
|-
! style="background:#efefef;" | Dichlorodifluoromethane
|- align="center"
| [[Image:Dichlorodifluoromethane]]
|-
! style="background:#efefef;" | 3D Structure
|- align="center"
|<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 150; cpk 25%;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>water.mol
HEADER NONAME 06-Dec-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 06-Dec-06 0 NONE 4
ATOM 1 Cl 0 -1.472 0.684 -0.000 0.00 0.00 Cl+0
ATOM 2 C 0 -0.000 -0.357 0.000 0.00 0.00 C+0
ATOM 3 Cl 0 1.472 0.684 -0.000 0.00 0.00 Cl+0
ATOM 4 F 0 0.000 -1.164 1.142 0.00 0.00 F+0
ATOM 5 F 0 -0.000 -1.164 -1.142 0.00 0.00 F+0
CONECT 1 2 0 0 0 NONE 10
CONECT 2 1 3 4 5 NONE 11
CONECT 3 2 0 0 0 NONE 12
CONECT 4 2 0 0 0 NONE 13
CONECT 5 2 0 0 0 NONE 14
END NONE 15
M END</inlineContents>
</jmolApplet>
</jmol>

----

{| cellpadding="2" cellspacing="2" align="ceter"

|- align="left"
! style="background:#ffdead;" | Chemical Name
| dichloro-difluoro-methane

|- align="left"
! style="background:#ffdead;" |Formula
| CCl2F2

|- align="left"
! style="background:#ffdead;" |Other Names
| Fluorocarbon 12, Refrigerant 12, Freon 12,
Propellant 12, Halon 122, FC 12, Freon F-12.

|- align="left"
! style="background:#ffdead;" |CAS No.
| [75-71-8]

|- align="left"
! style="background:#ffdead;" |Beilstein No.
| 1732393

|- align="left"
! style="background:#ffdead;" |Type of Substance
| Acyclic

|- align="left"
! style="background:#ffdead;" |Boiling Point
| -29.8°C / -21.6°F

|- align="left"
! style="background:#ffdead;" |Melting Point
| -157.7°C / -252°F

|- align="left"
! style="background:#ffdead;" |Density
| 1.293

|- align="left"
! style="background:#ffdead;" |Solubility
| Nearly insoluble in water;
solubale in most organic solvents.
|}
|}

It:Cyameluric Acid

2006-12-06T18:52:23Z

Dh405: /* History */

{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
! {{chembox header}} colspan="3" |2D Structure of Cyanmeluric Acid
|-
| align="center" colspan="3" bgcolour="#ffffff" | [[Image:Cyanmeluric Acid jaa05.gif]]
|-
! {{chembox header}} colspan="3" |3D structure of Cyanmeluric Acid<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>
HEADER NONAME 20-Nov-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 20-Nov-06 0 NONE 4
ATOM 1 O 0 -1.758 -3.611 0.001 0.00 0.00 O-1
ATOM 2 C 0 -1.166 -2.396 0.001 0.00 0.00 C+0
ATOM 3 N 0 0.161 -2.322 0.000 0.00 0.00 N+0
ATOM 4 C 0 0.766 -1.134 0.000 0.00 0.00 C+0
ATOM 5 N 0 0.000 0.000 0.000 0.00 0.00 N+0
ATOM 6 N 0 2.094 -1.016 -0.000 0.00 0.00 N+0
ATOM 7 C 0 2.658 0.188 -0.000 0.00 0.00 C+0
ATOM 8 O 0 4.006 0.283 -0.000 0.00 0.00 O-1
ATOM 9 N 0 1.930 1.300 -0.000 0.00 0.00 N+0
ATOM 10 C 0 0.599 1.231 0.001 0.00 0.00 C+0
ATOM 11 N 0 -0.167 2.321 -0.000 0.00 0.00 N+0
ATOM 12 C 0 -1.492 2.208 0.001 0.00 0.00 C+0
ATOM 13 O 0 -2.248 3.328 -0.000 0.00 0.00 O-1
ATOM 14 N 0 -2.091 1.021 0.001 0.00 0.00 N+0
ATOM 15 C 0 -1.366 -0.097 0.000 0.00 0.00 C+0
ATOM 16 N 0 -1.927 -1.305 -0.004 0.00 0.00 N+0
CONECT 1 2 0 0 0 NONE 21
CONECT 2 1 16 3 0 NONE 22
CONECT 3 2 4 0 0 NONE 23
CONECT 4 3 5 6 0 NONE 24
CONECT 5 4 10 15 0 NONE 25
CONECT 6 4 7 0 0 NONE 26
CONECT 7 6 8 9 0 NONE 27
CONECT 8 7 0 0 0 NONE 28
CONECT 9 7 10 0 0 NONE 29
CONECT 10 9 5 11 0 NONE 30
CONECT 11 10 12 0 0 NONE 31
CONECT 12 11 13 14 0 NONE 32
CONECT 13 12 0 0 0 NONE 33
CONECT 14 12 15 0 0 NONE 34
CONECT 15 14 5 16 0 NONE 35
CONECT 16 15 2 0 0 NONE 36
END NONE 37
</inlineContents>
</jmolApplet>
</jmol>
|-
! {{chembox header}} colspan="3" | Properties
|-
| colspan="1" |IUPAC Systematic Name
| colspan="2"|
|-
| colspan="1" |CA Index Name
| colspan="2" |1,3,4,6,7,9,9b-Heptaazaphenalene-2,5,8(1H,3H,6H)
-trione, tripotassium salt, hydrate (9CI)
|-
| colspan="1" |Other Names
| colspan="2" |Cyameluric acid, tripotassium salt, hydrate
|-
| colspan="1" |Molecular formula
| colspan="2" |C6N7O33-
|-
| colspan="1" |SMILES String
| colspan="2" |[O-]C1=NC(N23)=NC([O-])=NC2=NC([O-])=NC3=N1
|-
| colspan="1" |Molecular Mass
| colspan="2" |218.11
|-
| colspan="1" |Appearance
| colspan="2" |
|-
|colspan="1" |Beilstein Registry number
| colspan="2" |3842474
|-
| colspan="1" |CAS Registry Number
| colspan="2" |42431-24-3
|-
| Melting Point
| colspan="2" |
|-
|colspan="1" |Boiling point
| colspan="2" |
|-
|colspan="1" |Refractive index
| colspan="2" |

|}

==History==
[[Image:Heptazines.bmp]]

The compound show above is called tri-s-triazine or 1,3,4,6,7,9,9b-Heptaazaphenalene or cyamelurine, if we change three R group with three amino substituents it is called melem. In Melon the heptazine is polymerized with the tri-s-triazine units linked through an amine (NH) link.

Derivate of heptazine with three hydroxyl substituents is called Cyameluric acid. The first person to suggest a structure for cyameluric acid is Josef Loschmidt, at 1861. His structure is in fact a meta-cyclophane, but this at a time when cyclic compounds of any type were not widely recognised.

==Discovery of Cyameluric acid==
In 1937 a structure of '''cyameluric acid''', C6N7(OH)3, was proposed by ''Pauling'' and ''Sturdivant''. The structure differed greatly from those of previous scientists. This type of molecule seemed to fascinate Pauling; the last thing he wrote on the chalkboard in his office before his death in 1994 was an azide derivative of cyameluric acid. It has been preserved there to this day by his friends.

In 1850 Henneberg prepared salts of the acid, and in 1933 Professor E. C. Franklin suggested the structure:

[[Image:Franklin.bmp]]

Franklin's research led Pauling and Sturdivant to similar formulations as studied by Franklin; hydromelonic acid is related to cyameluric acid as cyanuric tricyanamide is to cyanuric acid.

The Pauling/Sturdivant structure for cyameluric acid is made up of 3 coplanar rings fused together, with all angles approximately equal to 120°, the structure of the cyamelurate ion is shown in the table on the right. It is a delocalised system, and can be represented in a similar way to ''Kekule's'' structure for benzene, in a conjugated form:

[[Image:Resonance.bmp]]

Infinite structures can be formed in a hydrogen bonding network.

This proposed structure seems to hold the best explanation of properties of cyameluric acid. The resonance forms account for the high stability and the acid strength. This structure also corresponds to the hydrolysis porducts and is therefore the most likely structure. Although there is no report of the crystal structure of cyameluric acid to date.

==Tautomeric==

As cyameluric acid has seventeen tautomers, which is the most stable one?
The seventeen tautomers of Cyameluric acid is showed below:

[[Image:Tautomeric1.jpg]]

[[Image:Tautomeric2.JPG]]

[[Image:Table 1.JPG]]

DFT calculations (B3LYP/6-31G*) have been carried out on the these tautomers and find out the C3h trioxo tautomer 258 is the most stable. Some energies and absolute NMR shieldings (GIAO) were calculated for 258 and other tri-s-triazines, including cyamelurine and Pauling mystery molecule.

== Tips==
The heptazine derivate with an azide substituent and two hydroxyl groups is called Linus Pauling's mystery molecule. Two theories attempt to lift the mystery. It is suggested that Pauling failed to solve the double helix structure of DNA before Watson and Crick because he viewed uracil as an amide and not as the tautomeric hydroxy compound. The other theory suggests that Pauling intented to use the compound as a potential spectroscopic label for binding to DNA.

==References==

1. [http://www.arkat-usa.org/ARKIVOC/JOURNAL_CONTENT/manuscripts/2004/EM-917KP%20as%20published%20mainmanuscript.pdf "Theroetical study of cyameluric acid and related compounds"]

2. ''Proceedings of the National Academy of Sciences of the Untied States of America'', Vol. 23, No. 12, pp. 615-620 : '''The Structure of Cyameluric Acid, Hydromelonic Acid, and Related Substance''' - Linus Pauling; J. H. Sturdivant

3. [http://en.wikipedia.org/wiki/Melem''Melem'']

It:Cyameluric Acid

2006-12-06T18:51:51Z

Dh405: /* References */

{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
! {{chembox header}} colspan="3" |2D Structure of Cyanmeluric Acid
|-
| align="center" colspan="3" bgcolour="#ffffff" | [[Image:Cyanmeluric Acid jaa05.gif]]
|-
! {{chembox header}} colspan="3" |3D structure of Cyanmeluric Acid<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>
HEADER NONAME 20-Nov-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 20-Nov-06 0 NONE 4
ATOM 1 O 0 -1.758 -3.611 0.001 0.00 0.00 O-1
ATOM 2 C 0 -1.166 -2.396 0.001 0.00 0.00 C+0
ATOM 3 N 0 0.161 -2.322 0.000 0.00 0.00 N+0
ATOM 4 C 0 0.766 -1.134 0.000 0.00 0.00 C+0
ATOM 5 N 0 0.000 0.000 0.000 0.00 0.00 N+0
ATOM 6 N 0 2.094 -1.016 -0.000 0.00 0.00 N+0
ATOM 7 C 0 2.658 0.188 -0.000 0.00 0.00 C+0
ATOM 8 O 0 4.006 0.283 -0.000 0.00 0.00 O-1
ATOM 9 N 0 1.930 1.300 -0.000 0.00 0.00 N+0
ATOM 10 C 0 0.599 1.231 0.001 0.00 0.00 C+0
ATOM 11 N 0 -0.167 2.321 -0.000 0.00 0.00 N+0
ATOM 12 C 0 -1.492 2.208 0.001 0.00 0.00 C+0
ATOM 13 O 0 -2.248 3.328 -0.000 0.00 0.00 O-1
ATOM 14 N 0 -2.091 1.021 0.001 0.00 0.00 N+0
ATOM 15 C 0 -1.366 -0.097 0.000 0.00 0.00 C+0
ATOM 16 N 0 -1.927 -1.305 -0.004 0.00 0.00 N+0
CONECT 1 2 0 0 0 NONE 21
CONECT 2 1 16 3 0 NONE 22
CONECT 3 2 4 0 0 NONE 23
CONECT 4 3 5 6 0 NONE 24
CONECT 5 4 10 15 0 NONE 25
CONECT 6 4 7 0 0 NONE 26
CONECT 7 6 8 9 0 NONE 27
CONECT 8 7 0 0 0 NONE 28
CONECT 9 7 10 0 0 NONE 29
CONECT 10 9 5 11 0 NONE 30
CONECT 11 10 12 0 0 NONE 31
CONECT 12 11 13 14 0 NONE 32
CONECT 13 12 0 0 0 NONE 33
CONECT 14 12 15 0 0 NONE 34
CONECT 15 14 5 16 0 NONE 35
CONECT 16 15 2 0 0 NONE 36
END NONE 37
</inlineContents>
</jmolApplet>
</jmol>
|-
! {{chembox header}} colspan="3" | Properties
|-
| colspan="1" |IUPAC Systematic Name
| colspan="2"|
|-
| colspan="1" |CA Index Name
| colspan="2" |1,3,4,6,7,9,9b-Heptaazaphenalene-2,5,8(1H,3H,6H)
-trione, tripotassium salt, hydrate (9CI)
|-
| colspan="1" |Other Names
| colspan="2" |Cyameluric acid, tripotassium salt, hydrate
|-
| colspan="1" |Molecular formula
| colspan="2" |C6N7O33-
|-
| colspan="1" |SMILES String
| colspan="2" |[O-]C1=NC(N23)=NC([O-])=NC2=NC([O-])=NC3=N1
|-
| colspan="1" |Molecular Mass
| colspan="2" |218.11
|-
| colspan="1" |Appearance
| colspan="2" |
|-
|colspan="1" |Beilstein Registry number
| colspan="2" |3842474
|-
| colspan="1" |CAS Registry Number
| colspan="2" |42431-24-3
|-
| Melting Point
| colspan="2" |
|-
|colspan="1" |Boiling point
| colspan="2" |
|-
|colspan="1" |Refractive index
| colspan="2" |

|}

===History===
[[Image:Heptazines.bmp]]

The compound show above is called tri-s-triazine or 1,3,4,6,7,9,9b-Heptaazaphenalene or cyamelurine, if we change three R group with three amino substituents it is called melem. In Melon the heptazine is polymerized with the tri-s-triazine units linked through an amine (NH) link.

Derivate of heptazine with three hydroxyl substituents is called Cyameluric acid. The first person to suggest a structure for cyameluric acid is Josef Loschmidt, at 1861. His structure is in fact a meta-cyclophane, but this at a time when cyclic compounds of any type were not widely recognised.

==Discovery of Cyameluric acid==
In 1937 a structure of '''cyameluric acid''', C6N7(OH)3, was proposed by ''Pauling'' and ''Sturdivant''. The structure differed greatly from those of previous scientists. This type of molecule seemed to fascinate Pauling; the last thing he wrote on the chalkboard in his office before his death in 1994 was an azide derivative of cyameluric acid. It has been preserved there to this day by his friends.

In 1850 Henneberg prepared salts of the acid, and in 1933 Professor E. C. Franklin suggested the structure:

[[Image:Franklin.bmp]]

Franklin's research led Pauling and Sturdivant to similar formulations as studied by Franklin; hydromelonic acid is related to cyameluric acid as cyanuric tricyanamide is to cyanuric acid.

The Pauling/Sturdivant structure for cyameluric acid is made up of 3 coplanar rings fused together, with all angles approximately equal to 120°, the structure of the cyamelurate ion is shown in the table on the right. It is a delocalised system, and can be represented in a similar way to ''Kekule's'' structure for benzene, in a conjugated form:

[[Image:Resonance.bmp]]

Infinite structures can be formed in a hydrogen bonding network.

This proposed structure seems to hold the best explanation of properties of cyameluric acid. The resonance forms account for the high stability and the acid strength. This structure also corresponds to the hydrolysis porducts and is therefore the most likely structure. Although there is no report of the crystal structure of cyameluric acid to date.

==Tautomeric==

As cyameluric acid has seventeen tautomers, which is the most stable one?
The seventeen tautomers of Cyameluric acid is showed below:

[[Image:Tautomeric1.jpg]]

[[Image:Tautomeric2.JPG]]

[[Image:Table 1.JPG]]

DFT calculations (B3LYP/6-31G*) have been carried out on the these tautomers and find out the C3h trioxo tautomer 258 is the most stable. Some energies and absolute NMR shieldings (GIAO) were calculated for 258 and other tri-s-triazines, including cyamelurine and Pauling mystery molecule.

== Tips==
The heptazine derivate with an azide substituent and two hydroxyl groups is called Linus Pauling's mystery molecule. Two theories attempt to lift the mystery. It is suggested that Pauling failed to solve the double helix structure of DNA before Watson and Crick because he viewed uracil as an amide and not as the tautomeric hydroxy compound. The other theory suggests that Pauling intented to use the compound as a potential spectroscopic label for binding to DNA.

==References==

1. [http://www.arkat-usa.org/ARKIVOC/JOURNAL_CONTENT/manuscripts/2004/EM-917KP%20as%20published%20mainmanuscript.pdf "Theroetical study of cyameluric acid and related compounds"]

2. ''Proceedings of the National Academy of Sciences of the Untied States of America'', Vol. 23, No. 12, pp. 615-620 : '''The Structure of Cyameluric Acid, Hydromelonic Acid, and Related Substance''' - Linus Pauling; J. H. Sturdivant

3. [http://en.wikipedia.org/wiki/Melem''Melem'']

It:Cyameluric Acid

2006-12-06T18:51:29Z

Dh405: /* Tips */

{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
! {{chembox header}} colspan="3" |2D Structure of Cyanmeluric Acid
|-
| align="center" colspan="3" bgcolour="#ffffff" | [[Image:Cyanmeluric Acid jaa05.gif]]
|-
! {{chembox header}} colspan="3" |3D structure of Cyanmeluric Acid<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>
HEADER NONAME 20-Nov-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 20-Nov-06 0 NONE 4
ATOM 1 O 0 -1.758 -3.611 0.001 0.00 0.00 O-1
ATOM 2 C 0 -1.166 -2.396 0.001 0.00 0.00 C+0
ATOM 3 N 0 0.161 -2.322 0.000 0.00 0.00 N+0
ATOM 4 C 0 0.766 -1.134 0.000 0.00 0.00 C+0
ATOM 5 N 0 0.000 0.000 0.000 0.00 0.00 N+0
ATOM 6 N 0 2.094 -1.016 -0.000 0.00 0.00 N+0
ATOM 7 C 0 2.658 0.188 -0.000 0.00 0.00 C+0
ATOM 8 O 0 4.006 0.283 -0.000 0.00 0.00 O-1
ATOM 9 N 0 1.930 1.300 -0.000 0.00 0.00 N+0
ATOM 10 C 0 0.599 1.231 0.001 0.00 0.00 C+0
ATOM 11 N 0 -0.167 2.321 -0.000 0.00 0.00 N+0
ATOM 12 C 0 -1.492 2.208 0.001 0.00 0.00 C+0
ATOM 13 O 0 -2.248 3.328 -0.000 0.00 0.00 O-1
ATOM 14 N 0 -2.091 1.021 0.001 0.00 0.00 N+0
ATOM 15 C 0 -1.366 -0.097 0.000 0.00 0.00 C+0
ATOM 16 N 0 -1.927 -1.305 -0.004 0.00 0.00 N+0
CONECT 1 2 0 0 0 NONE 21
CONECT 2 1 16 3 0 NONE 22
CONECT 3 2 4 0 0 NONE 23
CONECT 4 3 5 6 0 NONE 24
CONECT 5 4 10 15 0 NONE 25
CONECT 6 4 7 0 0 NONE 26
CONECT 7 6 8 9 0 NONE 27
CONECT 8 7 0 0 0 NONE 28
CONECT 9 7 10 0 0 NONE 29
CONECT 10 9 5 11 0 NONE 30
CONECT 11 10 12 0 0 NONE 31
CONECT 12 11 13 14 0 NONE 32
CONECT 13 12 0 0 0 NONE 33
CONECT 14 12 15 0 0 NONE 34
CONECT 15 14 5 16 0 NONE 35
CONECT 16 15 2 0 0 NONE 36
END NONE 37
</inlineContents>
</jmolApplet>
</jmol>
|-
! {{chembox header}} colspan="3" | Properties
|-
| colspan="1" |IUPAC Systematic Name
| colspan="2"|
|-
| colspan="1" |CA Index Name
| colspan="2" |1,3,4,6,7,9,9b-Heptaazaphenalene-2,5,8(1H,3H,6H)
-trione, tripotassium salt, hydrate (9CI)
|-
| colspan="1" |Other Names
| colspan="2" |Cyameluric acid, tripotassium salt, hydrate
|-
| colspan="1" |Molecular formula
| colspan="2" |C6N7O33-
|-
| colspan="1" |SMILES String
| colspan="2" |[O-]C1=NC(N23)=NC([O-])=NC2=NC([O-])=NC3=N1
|-
| colspan="1" |Molecular Mass
| colspan="2" |218.11
|-
| colspan="1" |Appearance
| colspan="2" |
|-
|colspan="1" |Beilstein Registry number
| colspan="2" |3842474
|-
| colspan="1" |CAS Registry Number
| colspan="2" |42431-24-3
|-
| Melting Point
| colspan="2" |
|-
|colspan="1" |Boiling point
| colspan="2" |
|-
|colspan="1" |Refractive index
| colspan="2" |

|}

===History===
[[Image:Heptazines.bmp]]

The compound show above is called tri-s-triazine or 1,3,4,6,7,9,9b-Heptaazaphenalene or cyamelurine, if we change three R group with three amino substituents it is called melem. In Melon the heptazine is polymerized with the tri-s-triazine units linked through an amine (NH) link.

Derivate of heptazine with three hydroxyl substituents is called Cyameluric acid. The first person to suggest a structure for cyameluric acid is Josef Loschmidt, at 1861. His structure is in fact a meta-cyclophane, but this at a time when cyclic compounds of any type were not widely recognised.

==Discovery of Cyameluric acid==
In 1937 a structure of '''cyameluric acid''', C6N7(OH)3, was proposed by ''Pauling'' and ''Sturdivant''. The structure differed greatly from those of previous scientists. This type of molecule seemed to fascinate Pauling; the last thing he wrote on the chalkboard in his office before his death in 1994 was an azide derivative of cyameluric acid. It has been preserved there to this day by his friends.

In 1850 Henneberg prepared salts of the acid, and in 1933 Professor E. C. Franklin suggested the structure:

[[Image:Franklin.bmp]]

Franklin's research led Pauling and Sturdivant to similar formulations as studied by Franklin; hydromelonic acid is related to cyameluric acid as cyanuric tricyanamide is to cyanuric acid.

The Pauling/Sturdivant structure for cyameluric acid is made up of 3 coplanar rings fused together, with all angles approximately equal to 120°, the structure of the cyamelurate ion is shown in the table on the right. It is a delocalised system, and can be represented in a similar way to ''Kekule's'' structure for benzene, in a conjugated form:

[[Image:Resonance.bmp]]

Infinite structures can be formed in a hydrogen bonding network.

This proposed structure seems to hold the best explanation of properties of cyameluric acid. The resonance forms account for the high stability and the acid strength. This structure also corresponds to the hydrolysis porducts and is therefore the most likely structure. Although there is no report of the crystal structure of cyameluric acid to date.

==Tautomeric==

As cyameluric acid has seventeen tautomers, which is the most stable one?
The seventeen tautomers of Cyameluric acid is showed below:

[[Image:Tautomeric1.jpg]]

[[Image:Tautomeric2.JPG]]

[[Image:Table 1.JPG]]

DFT calculations (B3LYP/6-31G*) have been carried out on the these tautomers and find out the C3h trioxo tautomer 258 is the most stable. Some energies and absolute NMR shieldings (GIAO) were calculated for 258 and other tri-s-triazines, including cyamelurine and Pauling mystery molecule.

== Tips==
The heptazine derivate with an azide substituent and two hydroxyl groups is called Linus Pauling's mystery molecule. Two theories attempt to lift the mystery. It is suggested that Pauling failed to solve the double helix structure of DNA before Watson and Crick because he viewed uracil as an amide and not as the tautomeric hydroxy compound. The other theory suggests that Pauling intented to use the compound as a potential spectroscopic label for binding to DNA.

==References==

1. [http://www.arkat-usa.org/ARKIVOC/JOURNAL_CONTENT/manuscripts/2004/EM-917KP%20as%20published%20mainmanuscript.pdf "Theroetical study of cyameluric acid and related compounds"]

2. ''Proceedings of the National Academy of Sciences of the Untied States of America'', Vol. 23, No. 12, pp. 615-620 : '''The Structure of Cyameluric Acid, Hydromelonic Acid, and Related Substance''' - Linus Pauling; J. H. Sturdivant

3. [http://en.wikipedia.org/wiki/Melem''Melem'']

It:Cyameluric Acid

2006-12-06T18:50:47Z

Dh405: /* Tautomeric */

{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
! {{chembox header}} colspan="3" |2D Structure of Cyanmeluric Acid
|-
| align="center" colspan="3" bgcolour="#ffffff" | [[Image:Cyanmeluric Acid jaa05.gif]]
|-
! {{chembox header}} colspan="3" |3D structure of Cyanmeluric Acid<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>
HEADER NONAME 20-Nov-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 20-Nov-06 0 NONE 4
ATOM 1 O 0 -1.758 -3.611 0.001 0.00 0.00 O-1
ATOM 2 C 0 -1.166 -2.396 0.001 0.00 0.00 C+0
ATOM 3 N 0 0.161 -2.322 0.000 0.00 0.00 N+0
ATOM 4 C 0 0.766 -1.134 0.000 0.00 0.00 C+0
ATOM 5 N 0 0.000 0.000 0.000 0.00 0.00 N+0
ATOM 6 N 0 2.094 -1.016 -0.000 0.00 0.00 N+0
ATOM 7 C 0 2.658 0.188 -0.000 0.00 0.00 C+0
ATOM 8 O 0 4.006 0.283 -0.000 0.00 0.00 O-1
ATOM 9 N 0 1.930 1.300 -0.000 0.00 0.00 N+0
ATOM 10 C 0 0.599 1.231 0.001 0.00 0.00 C+0
ATOM 11 N 0 -0.167 2.321 -0.000 0.00 0.00 N+0
ATOM 12 C 0 -1.492 2.208 0.001 0.00 0.00 C+0
ATOM 13 O 0 -2.248 3.328 -0.000 0.00 0.00 O-1
ATOM 14 N 0 -2.091 1.021 0.001 0.00 0.00 N+0
ATOM 15 C 0 -1.366 -0.097 0.000 0.00 0.00 C+0
ATOM 16 N 0 -1.927 -1.305 -0.004 0.00 0.00 N+0
CONECT 1 2 0 0 0 NONE 21
CONECT 2 1 16 3 0 NONE 22
CONECT 3 2 4 0 0 NONE 23
CONECT 4 3 5 6 0 NONE 24
CONECT 5 4 10 15 0 NONE 25
CONECT 6 4 7 0 0 NONE 26
CONECT 7 6 8 9 0 NONE 27
CONECT 8 7 0 0 0 NONE 28
CONECT 9 7 10 0 0 NONE 29
CONECT 10 9 5 11 0 NONE 30
CONECT 11 10 12 0 0 NONE 31
CONECT 12 11 13 14 0 NONE 32
CONECT 13 12 0 0 0 NONE 33
CONECT 14 12 15 0 0 NONE 34
CONECT 15 14 5 16 0 NONE 35
CONECT 16 15 2 0 0 NONE 36
END NONE 37
</inlineContents>
</jmolApplet>
</jmol>
|-
! {{chembox header}} colspan="3" | Properties
|-
| colspan="1" |IUPAC Systematic Name
| colspan="2"|
|-
| colspan="1" |CA Index Name
| colspan="2" |1,3,4,6,7,9,9b-Heptaazaphenalene-2,5,8(1H,3H,6H)
-trione, tripotassium salt, hydrate (9CI)
|-
| colspan="1" |Other Names
| colspan="2" |Cyameluric acid, tripotassium salt, hydrate
|-
| colspan="1" |Molecular formula
| colspan="2" |C6N7O33-
|-
| colspan="1" |SMILES String
| colspan="2" |[O-]C1=NC(N23)=NC([O-])=NC2=NC([O-])=NC3=N1
|-
| colspan="1" |Molecular Mass
| colspan="2" |218.11
|-
| colspan="1" |Appearance
| colspan="2" |
|-
|colspan="1" |Beilstein Registry number
| colspan="2" |3842474
|-
| colspan="1" |CAS Registry Number
| colspan="2" |42431-24-3
|-
| Melting Point
| colspan="2" |
|-
|colspan="1" |Boiling point
| colspan="2" |
|-
|colspan="1" |Refractive index
| colspan="2" |

|}

===History===
[[Image:Heptazines.bmp]]

The compound show above is called tri-s-triazine or 1,3,4,6,7,9,9b-Heptaazaphenalene or cyamelurine, if we change three R group with three amino substituents it is called melem. In Melon the heptazine is polymerized with the tri-s-triazine units linked through an amine (NH) link.

Derivate of heptazine with three hydroxyl substituents is called Cyameluric acid. The first person to suggest a structure for cyameluric acid is Josef Loschmidt, at 1861. His structure is in fact a meta-cyclophane, but this at a time when cyclic compounds of any type were not widely recognised.

==Discovery of Cyameluric acid==
In 1937 a structure of '''cyameluric acid''', C6N7(OH)3, was proposed by ''Pauling'' and ''Sturdivant''. The structure differed greatly from those of previous scientists. This type of molecule seemed to fascinate Pauling; the last thing he wrote on the chalkboard in his office before his death in 1994 was an azide derivative of cyameluric acid. It has been preserved there to this day by his friends.

In 1850 Henneberg prepared salts of the acid, and in 1933 Professor E. C. Franklin suggested the structure:

[[Image:Franklin.bmp]]

Franklin's research led Pauling and Sturdivant to similar formulations as studied by Franklin; hydromelonic acid is related to cyameluric acid as cyanuric tricyanamide is to cyanuric acid.

The Pauling/Sturdivant structure for cyameluric acid is made up of 3 coplanar rings fused together, with all angles approximately equal to 120°, the structure of the cyamelurate ion is shown in the table on the right. It is a delocalised system, and can be represented in a similar way to ''Kekule's'' structure for benzene, in a conjugated form:

[[Image:Resonance.bmp]]

Infinite structures can be formed in a hydrogen bonding network.

This proposed structure seems to hold the best explanation of properties of cyameluric acid. The resonance forms account for the high stability and the acid strength. This structure also corresponds to the hydrolysis porducts and is therefore the most likely structure. Although there is no report of the crystal structure of cyameluric acid to date.

==Tautomeric==

As cyameluric acid has seventeen tautomers, which is the most stable one?
The seventeen tautomers of Cyameluric acid is showed below:

[[Image:Tautomeric1.jpg]]

[[Image:Tautomeric2.JPG]]

[[Image:Table 1.JPG]]

DFT calculations (B3LYP/6-31G*) have been carried out on the these tautomers and find out the C3h trioxo tautomer 258 is the most stable. Some energies and absolute NMR shieldings (GIAO) were calculated for 258 and other tri-s-triazines, including cyamelurine and Pauling mystery molecule.

== Tips==
The heptazine derivate with an azide substituent and two hydroxyl groups is called Linus Pauling's mystery molecule. Two theories attempt to lift the mystery. It is suggested that Pauling failed to solve the double helix structure of DNA before Watson and Crick because he viewed uracil as an amide and not as the tautomeric hydroxy compound. The other theory suggests that Pauling intented to use the compound as a potential spectroscopic label for binding to DNA.

==References==

1. [http://www.arkat-usa.org/ARKIVOC/JOURNAL_CONTENT/manuscripts/2004/EM-917KP%20as%20published%20mainmanuscript.pdf "Theroetical study of cyameluric acid and related compounds"]

2. ''Proceedings of the National Academy of Sciences of the Untied States of America'', Vol. 23, No. 12, pp. 615-620 : '''The Structure of Cyameluric Acid, Hydromelonic Acid, and Related Substance''' - Linus Pauling; J. H. Sturdivant

3. [http://en.wikipedia.org/wiki/Melem''Melem'']

File:Table 1.JPG

2006-12-06T18:46:06Z

Dh405:

It:Cyameluric Acid

2006-12-06T18:37:16Z

Dh405: /* Tautomeric */

{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
! {{chembox header}} colspan="3" |2D Structure of Cyanmeluric Acid
|-
| align="center" colspan="3" bgcolour="#ffffff" | [[Image:Cyanmeluric Acid jaa05.gif]]
|-
! {{chembox header}} colspan="3" |3D structure of Cyanmeluric Acid<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>
HEADER NONAME 20-Nov-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 20-Nov-06 0 NONE 4
ATOM 1 O 0 -1.758 -3.611 0.001 0.00 0.00 O-1
ATOM 2 C 0 -1.166 -2.396 0.001 0.00 0.00 C+0
ATOM 3 N 0 0.161 -2.322 0.000 0.00 0.00 N+0
ATOM 4 C 0 0.766 -1.134 0.000 0.00 0.00 C+0
ATOM 5 N 0 0.000 0.000 0.000 0.00 0.00 N+0
ATOM 6 N 0 2.094 -1.016 -0.000 0.00 0.00 N+0
ATOM 7 C 0 2.658 0.188 -0.000 0.00 0.00 C+0
ATOM 8 O 0 4.006 0.283 -0.000 0.00 0.00 O-1
ATOM 9 N 0 1.930 1.300 -0.000 0.00 0.00 N+0
ATOM 10 C 0 0.599 1.231 0.001 0.00 0.00 C+0
ATOM 11 N 0 -0.167 2.321 -0.000 0.00 0.00 N+0
ATOM 12 C 0 -1.492 2.208 0.001 0.00 0.00 C+0
ATOM 13 O 0 -2.248 3.328 -0.000 0.00 0.00 O-1
ATOM 14 N 0 -2.091 1.021 0.001 0.00 0.00 N+0
ATOM 15 C 0 -1.366 -0.097 0.000 0.00 0.00 C+0
ATOM 16 N 0 -1.927 -1.305 -0.004 0.00 0.00 N+0
CONECT 1 2 0 0 0 NONE 21
CONECT 2 1 16 3 0 NONE 22
CONECT 3 2 4 0 0 NONE 23
CONECT 4 3 5 6 0 NONE 24
CONECT 5 4 10 15 0 NONE 25
CONECT 6 4 7 0 0 NONE 26
CONECT 7 6 8 9 0 NONE 27
CONECT 8 7 0 0 0 NONE 28
CONECT 9 7 10 0 0 NONE 29
CONECT 10 9 5 11 0 NONE 30
CONECT 11 10 12 0 0 NONE 31
CONECT 12 11 13 14 0 NONE 32
CONECT 13 12 0 0 0 NONE 33
CONECT 14 12 15 0 0 NONE 34
CONECT 15 14 5 16 0 NONE 35
CONECT 16 15 2 0 0 NONE 36
END NONE 37
</inlineContents>
</jmolApplet>
</jmol>
|-
! {{chembox header}} colspan="3" | Properties
|-
| colspan="1" |IUPAC Systematic Name
| colspan="2"|
|-
| colspan="1" |CA Index Name
| colspan="2" |1,3,4,6,7,9,9b-Heptaazaphenalene-2,5,8(1H,3H,6H)
-trione, tripotassium salt, hydrate (9CI)
|-
| colspan="1" |Other Names
| colspan="2" |Cyameluric acid, tripotassium salt, hydrate
|-
| colspan="1" |Molecular formula
| colspan="2" |C6N7O33-
|-
| colspan="1" |SMILES String
| colspan="2" |[O-]C1=NC(N23)=NC([O-])=NC2=NC([O-])=NC3=N1
|-
| colspan="1" |Molecular Mass
| colspan="2" |218.11
|-
| colspan="1" |Appearance
| colspan="2" |
|-
|colspan="1" |Beilstein Registry number
| colspan="2" |3842474
|-
| colspan="1" |CAS Registry Number
| colspan="2" |42431-24-3
|-
| Melting Point
| colspan="2" |
|-
|colspan="1" |Boiling point
| colspan="2" |
|-
|colspan="1" |Refractive index
| colspan="2" |

|}

===History===
[[Image:Heptazines.bmp]]

The compound show above is called tri-s-triazine or 1,3,4,6,7,9,9b-Heptaazaphenalene or cyamelurine, if we change three R group with three amino substituents it is called melem. In Melon the heptazine is polymerized with the tri-s-triazine units linked through an amine (NH) link.

Derivate of heptazine with three hydroxyl substituents is called Cyameluric acid. The first person to suggest a structure for cyameluric acid is Josef Loschmidt, at 1861. His structure is in fact a meta-cyclophane, but this at a time when cyclic compounds of any type were not widely recognised.

==Discovery of Cyameluric acid==
In 1937 a structure of '''cyameluric acid''', C6N7(OH)3, was proposed by ''Pauling'' and ''Sturdivant''. The structure differed greatly from those of previous scientists. This type of molecule seemed to fascinate Pauling; the last thing he wrote on the chalkboard in his office before his death in 1994 was an azide derivative of cyameluric acid. It has been preserved there to this day by his friends.

In 1850 Henneberg prepared salts of the acid, and in 1933 Professor E. C. Franklin suggested the structure:

[[Image:Franklin.bmp]]

Franklin's research led Pauling and Sturdivant to similar formulations as studied by Franklin; hydromelonic acid is related to cyameluric acid as cyanuric tricyanamide is to cyanuric acid.

The Pauling/Sturdivant structure for cyameluric acid is made up of 3 coplanar rings fused together, with all angles approximately equal to 120°, the structure of the cyamelurate ion is shown in the table on the right. It is a delocalised system, and can be represented in a similar way to ''Kekule's'' structure for benzene, in a conjugated form:

[[Image:Resonance.bmp]]

Infinite structures can be formed in a hydrogen bonding network.

This proposed structure seems to hold the best explanation of properties of cyameluric acid. The resonance forms account for the high stability and the acid strength. This structure also corresponds to the hydrolysis porducts and is therefore the most likely structure. Although there is no report of the crystal structure of cyameluric acid to date.

==Tautomeric==

The seventeen tautomers of Cyameluric acid is show below:

[[Image:Tautomeric1.jpg]]

[[Image:Tautomeric2.JPG]]

As cyameluric acid has seventeen tautomers, which is the most stable one? DFT calculations (B3LYP/6-31G*) have been carried out on the these tautomers and find out the C3h trioxo tautomer 258 is the most stable. Some energies and absolute NMR shieldings (GIAO) were calculated for 258 and other tri-s-triazines, including cyamelurine and Pauling mystery molecule.

== Tips==
The heptazine derivate with an azide substituent and two hydroxyl groups is called Linus Pauling's mystery molecule. Two theories attempt to lift the mystery. It is suggested that Pauling failed to solve the double helix structure of DNA before Watson and Crick because he viewed uracil as an amide and not as the tautomeric hydroxy compound. The other theory suggests that Pauling intented to use the compound as a potential spectroscopic label for binding to DNA.

==References==

1. [http://www.arkat-usa.org/ARKIVOC/JOURNAL_CONTENT/manuscripts/2004/EM-917KP%20as%20published%20mainmanuscript.pdf "Theroetical study of cyameluric acid and related compounds"]

2. ''Proceedings of the National Academy of Sciences of the Untied States of America'', Vol. 23, No. 12, pp. 615-620 : '''The Structure of Cyameluric Acid, Hydromelonic Acid, and Related Substance''' - Linus Pauling; J. H. Sturdivant

3. [http://en.wikipedia.org/wiki/Melem''Melem'']

It:Cyameluric Acid

2006-12-06T18:35:20Z

Dh405: /* Discovery of Cyameluric acid */

{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
! {{chembox header}} colspan="3" |2D Structure of Cyanmeluric Acid
|-
| align="center" colspan="3" bgcolour="#ffffff" | [[Image:Cyanmeluric Acid jaa05.gif]]
|-
! {{chembox header}} colspan="3" |3D structure of Cyanmeluric Acid<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>
HEADER NONAME 20-Nov-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 20-Nov-06 0 NONE 4
ATOM 1 O 0 -1.758 -3.611 0.001 0.00 0.00 O-1
ATOM 2 C 0 -1.166 -2.396 0.001 0.00 0.00 C+0
ATOM 3 N 0 0.161 -2.322 0.000 0.00 0.00 N+0
ATOM 4 C 0 0.766 -1.134 0.000 0.00 0.00 C+0
ATOM 5 N 0 0.000 0.000 0.000 0.00 0.00 N+0
ATOM 6 N 0 2.094 -1.016 -0.000 0.00 0.00 N+0
ATOM 7 C 0 2.658 0.188 -0.000 0.00 0.00 C+0
ATOM 8 O 0 4.006 0.283 -0.000 0.00 0.00 O-1
ATOM 9 N 0 1.930 1.300 -0.000 0.00 0.00 N+0
ATOM 10 C 0 0.599 1.231 0.001 0.00 0.00 C+0
ATOM 11 N 0 -0.167 2.321 -0.000 0.00 0.00 N+0
ATOM 12 C 0 -1.492 2.208 0.001 0.00 0.00 C+0
ATOM 13 O 0 -2.248 3.328 -0.000 0.00 0.00 O-1
ATOM 14 N 0 -2.091 1.021 0.001 0.00 0.00 N+0
ATOM 15 C 0 -1.366 -0.097 0.000 0.00 0.00 C+0
ATOM 16 N 0 -1.927 -1.305 -0.004 0.00 0.00 N+0
CONECT 1 2 0 0 0 NONE 21
CONECT 2 1 16 3 0 NONE 22
CONECT 3 2 4 0 0 NONE 23
CONECT 4 3 5 6 0 NONE 24
CONECT 5 4 10 15 0 NONE 25
CONECT 6 4 7 0 0 NONE 26
CONECT 7 6 8 9 0 NONE 27
CONECT 8 7 0 0 0 NONE 28
CONECT 9 7 10 0 0 NONE 29
CONECT 10 9 5 11 0 NONE 30
CONECT 11 10 12 0 0 NONE 31
CONECT 12 11 13 14 0 NONE 32
CONECT 13 12 0 0 0 NONE 33
CONECT 14 12 15 0 0 NONE 34
CONECT 15 14 5 16 0 NONE 35
CONECT 16 15 2 0 0 NONE 36
END NONE 37
</inlineContents>
</jmolApplet>
</jmol>
|-
! {{chembox header}} colspan="3" | Properties
|-
| colspan="1" |IUPAC Systematic Name
| colspan="2"|
|-
| colspan="1" |CA Index Name
| colspan="2" |1,3,4,6,7,9,9b-Heptaazaphenalene-2,5,8(1H,3H,6H)
-trione, tripotassium salt, hydrate (9CI)
|-
| colspan="1" |Other Names
| colspan="2" |Cyameluric acid, tripotassium salt, hydrate
|-
| colspan="1" |Molecular formula
| colspan="2" |C6N7O33-
|-
| colspan="1" |SMILES String
| colspan="2" |[O-]C1=NC(N23)=NC([O-])=NC2=NC([O-])=NC3=N1
|-
| colspan="1" |Molecular Mass
| colspan="2" |218.11
|-
| colspan="1" |Appearance
| colspan="2" |
|-
|colspan="1" |Beilstein Registry number
| colspan="2" |3842474
|-
| colspan="1" |CAS Registry Number
| colspan="2" |42431-24-3
|-
| Melting Point
| colspan="2" |
|-
|colspan="1" |Boiling point
| colspan="2" |
|-
|colspan="1" |Refractive index
| colspan="2" |

|}

===History===
[[Image:Heptazines.bmp]]

The compound show above is called tri-s-triazine or 1,3,4,6,7,9,9b-Heptaazaphenalene or cyamelurine, if we change three R group with three amino substituents it is called melem. In Melon the heptazine is polymerized with the tri-s-triazine units linked through an amine (NH) link.

Derivate of heptazine with three hydroxyl substituents is called Cyameluric acid. The first person to suggest a structure for cyameluric acid is Josef Loschmidt, at 1861. His structure is in fact a meta-cyclophane, but this at a time when cyclic compounds of any type were not widely recognised.

==Discovery of Cyameluric acid==
In 1937 a structure of '''cyameluric acid''', C6N7(OH)3, was proposed by ''Pauling'' and ''Sturdivant''. The structure differed greatly from those of previous scientists. This type of molecule seemed to fascinate Pauling; the last thing he wrote on the chalkboard in his office before his death in 1994 was an azide derivative of cyameluric acid. It has been preserved there to this day by his friends.

In 1850 Henneberg prepared salts of the acid, and in 1933 Professor E. C. Franklin suggested the structure:

[[Image:Franklin.bmp]]

Franklin's research led Pauling and Sturdivant to similar formulations as studied by Franklin; hydromelonic acid is related to cyameluric acid as cyanuric tricyanamide is to cyanuric acid.

The Pauling/Sturdivant structure for cyameluric acid is made up of 3 coplanar rings fused together, with all angles approximately equal to 120°, the structure of the cyamelurate ion is shown in the table on the right. It is a delocalised system, and can be represented in a similar way to ''Kekule's'' structure for benzene, in a conjugated form:

[[Image:Resonance.bmp]]

Infinite structures can be formed in a hydrogen bonding network.

This proposed structure seems to hold the best explanation of properties of cyameluric acid. The resonance forms account for the high stability and the acid strength. This structure also corresponds to the hydrolysis porducts and is therefore the most likely structure. Although there is no report of the crystal structure of cyameluric acid to date.

==Tautomeric==

[[Image:Tautomeric1.jpg]]

[[Image:Tautomeric2.JPG]]

As cyameluric acid has seventeen tautomers, which is the most stable one? DFT calculations (B3LYP/6-31G*) have been carried out on the these tautomers and find out the C3h trioxo tautomer 258 is the most stable. Some energies and absolute NMR shieldings (GIAO) were calculated for 258 and other tri-s-triazines, including cyamelurine and Pauling mystery molecule.

== Tips==
The heptazine derivate with an azide substituent and two hydroxyl groups is called Linus Pauling's mystery molecule. Two theories attempt to lift the mystery. It is suggested that Pauling failed to solve the double helix structure of DNA before Watson and Crick because he viewed uracil as an amide and not as the tautomeric hydroxy compound. The other theory suggests that Pauling intented to use the compound as a potential spectroscopic label for binding to DNA.

==References==

1. [http://www.arkat-usa.org/ARKIVOC/JOURNAL_CONTENT/manuscripts/2004/EM-917KP%20as%20published%20mainmanuscript.pdf "Theroetical study of cyameluric acid and related compounds"]

2. ''Proceedings of the National Academy of Sciences of the Untied States of America'', Vol. 23, No. 12, pp. 615-620 : '''The Structure of Cyameluric Acid, Hydromelonic Acid, and Related Substance''' - Linus Pauling; J. H. Sturdivant

3. [http://en.wikipedia.org/wiki/Melem''Melem'']

File:Tautomeric2.JPG

2006-12-06T18:27:10Z

Dh405:

File:Tautomeric1.jpg

2006-12-06T18:26:45Z

Dh405:

It:dichlorodifluromethane

2006-12-06T18:11:20Z

Dh405:

=='''Dichlorodifluoromethane(CCl2F2)'''==
{| border="1" cellpadding="5" cellspacing="0" align="center"
|-
! style="background:#efefef;" | Dichlorodifluoromethane
|- align="center"
| [[Image:Dichlorodifluoromethane]]
|-
! style="background:#efefef;" | 3D Structure
|- align="center"
|<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 150; cpk 25%;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>water.mol
HEADER NONAME 06-Dec-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 06-Dec-06 0 NONE 4
ATOM 1 Cl 0 -1.472 0.684 -0.000 0.00 0.00 Cl+0
ATOM 2 C 0 -0.000 -0.357 0.000 0.00 0.00 C+0
ATOM 3 Cl 0 1.472 0.684 -0.000 0.00 0.00 Cl+0
ATOM 4 F 0 0.000 -1.164 1.142 0.00 0.00 F+0
ATOM 5 F 0 -0.000 -1.164 -1.142 0.00 0.00 F+0
CONECT 1 2 0 0 0 NONE 10
CONECT 2 1 3 4 5 NONE 11
CONECT 3 2 0 0 0 NONE 12
CONECT 4 2 0 0 0 NONE 13
CONECT 5 2 0 0 0 NONE 14
END NONE 15
M END</inlineContents>
</jmolApplet>
</jmol>

----

{| cellpadding="2" cellspacing="2" align="ceter"

|- align="left"
! style="background:#ffdead;" | Chemical Name
| dichloro-difluoro-methane

|- align="left"
! style="background:#ffdead;" |Formula
| CCl2F2

|- align="left"
! style="background:#ffdead;" |Other Names
| Fluorocarbon 12, Refrigerant 12, Freon 12,
Propellant 12, Halon 122, FC 12, Freon F-12.

|- align="left"
! style="background:#ffdead;" |CAS No.
| [75-71-8]

|- align="left"
! style="background:#ffdead;" |Beilstein No.
| 1732393

|- align="left"
! style="background:#ffdead;" |Type of Substance
| Acyclic

|- align="left"
! style="background:#ffdead;" |Boiling Point
| -29.8°C / -21.6°F

|- align="left"
! style="background:#ffdead;" |Melting Point
| -157.7°C / -252°F

|- align="left"
! style="background:#ffdead;" |Solubility
| Nearly insoluble in water;
solubale in most organic solvents.
|}
|}

It:dichlorodifluromethane

2006-12-06T18:03:03Z

Dh405:

=='''Dichlorodifluoromethane(CCl2F2)'''==
{| border="1" cellpadding="5" cellspacing="0" align="center"
|-
! style="background:#efefef;" | Dichlorodifluoromethane
|- align="center"
| [[Image:Dichlorodifluoromethane]]
|-
! style="background:#efefef;" | 3D Structure
|- align="center"
|<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 150; cpk 25%;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>water.mol
HEADER NONAME 06-Dec-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 06-Dec-06 0 NONE 4
ATOM 1 Cl 0 -1.472 0.684 -0.000 0.00 0.00 Cl+0
ATOM 2 C 0 -0.000 -0.357 0.000 0.00 0.00 C+0
ATOM 3 Cl 0 1.472 0.684 -0.000 0.00 0.00 Cl+0
ATOM 4 F 0 0.000 -1.164 1.142 0.00 0.00 F+0
ATOM 5 F 0 -0.000 -1.164 -1.142 0.00 0.00 F+0
CONECT 1 2 0 0 0 NONE 10
CONECT 2 1 3 4 5 NONE 11
CONECT 3 2 0 0 0 NONE 12
CONECT 4 2 0 0 0 NONE 13
CONECT 5 2 0 0 0 NONE 14
END NONE 15
M END</inlineContents>
</jmolApplet>
</jmol>

----

{| cellpadding="2" cellspacing="2" align="ceter"

|- align="left"
! style="background:#ffdead;" | Chemical Name
| dichloro-difluoro-methane

|- align="left"
! style="background:#ffdead;" |Formula
| CCl2F2

|- align="left"
! style="background:#ffdead;" |Other Names
| Fluorocarbon 12, Refrigerant 12, Freon 12,
Propellant 12, Halon 122, FC 12, Freon F-12.

|- align="left"
! style="background:#ffdead;" |CAS No.
| [75-71-8]

|- align="left"
! style="background:#ffdead;" |Beilstein No.
| 1732393

|- align="left"
! style="background:#ffdead;" |Type of Substance
| Acyclic

|- align="left"
! style="background:#ffdead;" |Boiling Point
| -29.8°C / -21.6°F

|- align="left"
! style="background:#ffdead;" |Melting Point
| -157.7°C / -252°F

|- align="left"
! style="background:#ffdead;" |Solubility
| Nearly insoluble in water;
solubale in most organic solvents.
|}
|}

File:Tautomeric.bmp

2006-12-06T17:22:13Z

Dh405:

It:dichlorodifluromethane

2006-12-06T17:16:30Z

Dh405:

It:Cyameluric Acid

2006-12-06T15:45:43Z

Dh405: /* References */

{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
! {{chembox header}} colspan="3" |2D Structure of Cyanmeluric Acid
|-
| align="center" colspan="3" bgcolour="#ffffff" | [[Image:Cyanmeluric Acid jaa05.gif]]
|-
! {{chembox header}} colspan="3" |3D structure of Cyanmeluric Acid<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>
HEADER NONAME 20-Nov-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 20-Nov-06 0 NONE 4
ATOM 1 O 0 -1.758 -3.611 0.001 0.00 0.00 O-1
ATOM 2 C 0 -1.166 -2.396 0.001 0.00 0.00 C+0
ATOM 3 N 0 0.161 -2.322 0.000 0.00 0.00 N+0
ATOM 4 C 0 0.766 -1.134 0.000 0.00 0.00 C+0
ATOM 5 N 0 0.000 0.000 0.000 0.00 0.00 N+0
ATOM 6 N 0 2.094 -1.016 -0.000 0.00 0.00 N+0
ATOM 7 C 0 2.658 0.188 -0.000 0.00 0.00 C+0
ATOM 8 O 0 4.006 0.283 -0.000 0.00 0.00 O-1
ATOM 9 N 0 1.930 1.300 -0.000 0.00 0.00 N+0
ATOM 10 C 0 0.599 1.231 0.001 0.00 0.00 C+0
ATOM 11 N 0 -0.167 2.321 -0.000 0.00 0.00 N+0
ATOM 12 C 0 -1.492 2.208 0.001 0.00 0.00 C+0
ATOM 13 O 0 -2.248 3.328 -0.000 0.00 0.00 O-1
ATOM 14 N 0 -2.091 1.021 0.001 0.00 0.00 N+0
ATOM 15 C 0 -1.366 -0.097 0.000 0.00 0.00 C+0
ATOM 16 N 0 -1.927 -1.305 -0.004 0.00 0.00 N+0
CONECT 1 2 0 0 0 NONE 21
CONECT 2 1 16 3 0 NONE 22
CONECT 3 2 4 0 0 NONE 23
CONECT 4 3 5 6 0 NONE 24
CONECT 5 4 10 15 0 NONE 25
CONECT 6 4 7 0 0 NONE 26
CONECT 7 6 8 9 0 NONE 27
CONECT 8 7 0 0 0 NONE 28
CONECT 9 7 10 0 0 NONE 29
CONECT 10 9 5 11 0 NONE 30
CONECT 11 10 12 0 0 NONE 31
CONECT 12 11 13 14 0 NONE 32
CONECT 13 12 0 0 0 NONE 33
CONECT 14 12 15 0 0 NONE 34
CONECT 15 14 5 16 0 NONE 35
CONECT 16 15 2 0 0 NONE 36
END NONE 37
</inlineContents>
</jmolApplet>
</jmol>
|-
! {{chembox header}} colspan="3" | Properties
|-
| colspan="1" |IUPAC Systematic Name
| colspan="2"|
|-
| colspan="1" |CA Index Name
| colspan="2" |1,3,4,6,7,9,9b-Heptaazaphenalene-2,5,8(1H,3H,6H)
-trione, tripotassium salt, hydrate (9CI)
|-
| colspan="1" |Other Names
| colspan="2" |Cyameluric acid, tripotassium salt, hydrate
|-
| colspan="1" |Molecular formula
| colspan="2" |C6N7O33-
|-
| colspan="1" |SMILES String
| colspan="2" |[O-]C1=NC(N23)=NC([O-])=NC2=NC([O-])=NC3=N1
|-
| colspan="1" |Molecular Mass
| colspan="2" |218.11
|-
| colspan="1" |Appearance
| colspan="2" |
|-
|colspan="1" |Beilstein Registry number
| colspan="2" |3842474
|-
| colspan="1" |CAS Registry Number
| colspan="2" |42431-24-3
|-
| Melting Point
| colspan="2" |
|-
|colspan="1" |Boiling point
| colspan="2" |
|-
|colspan="1" |Refractive index
| colspan="2" |

|}

===History===
[[Image:Heptazines.bmp]]

The compound show above is called tri-s-triazine or 1,3,4,6,7,9,9b-Heptaazaphenalene or cyamelurine, if we change three R group with three amino substituents it is called melem. In Melon the heptazine is polymerized with the tri-s-triazine units linked through an amine (NH) link.

Derivate of heptazine with three hydroxyl substituents is called Cyameluric acid. The first person to suggest a structure for cyameluric acid is Josef Loschmidt, at 1861. His structure is in fact a meta-cyclophane, but this at a time when cyclic compounds of any type were not widely recognised.

==Discovery of Cyameluric acid==
In 1937 a structure of '''cyameluric acid''', C6N7(OH)3, was proposed by ''Pauling'' and ''Sturdivant''. The structure differed greatly from those of previous scientists. This type of molecule seemed to fascinate Pauling; the last thing he wrote on the chalkboard in his office before his death in 1994 was an azide derivative of cyameluric acid. It has been preserved there to this day by his friends.

In 1850 Henneberg prepared salts of the acid, and in 1933 Professor E. C. Franklin suggested the structure:

[[Image:Franklin.bmp]]

Franklin's research led Pauling and Sturdivant to similar formulations as studied by Franklin; hydromelonic acid is related to cyameluric acid as cyanuric tricyanamide is to cyanuric acid.

The Pauling/Sturdivant structure for cyameluric acid is made up of 3 coplanar rings fused together, with all angles approximately equal to 120°, the structure of the cyamelurate ion is shown in the table on the right. It is a delocalised system, and can be represented in a similar way to ''Kekule's'' structure for benzene, in a conjugated form:

[[Image:Resonance.bmp]]

Infinite structures can be formed in a hydrogen bonding network.

This proposed structure seems to hold the best explanation of properties of cyameluric acid. The resonance forms account for the high stability and the acid strength. This structure also corresponds to the hydrolysis porducts and is therefore the most likely structure. Although there is no report of the crystal structure of cyameluric acid to date.

As cyameluric acid has seventeen tautomers, which is the most stable one? DFT calculations (B3LYP/6-31G*) have been carried out on the these tautomers and find out the C3h trioxo tautomer 258 is the most stable. Some energies and absolute NMR shieldings (GIAO) were calculated for 258 and other tri-s-triazines, including cyamelurine and Pauling mystery molecule.

== Tips==
The heptazine derivate with an azide substituent and two hydroxyl groups is called Linus Pauling's mystery molecule. Two theories attempt to lift the mystery. It is suggested that Pauling failed to solve the double helix structure of DNA before Watson and Crick because he viewed uracil as an amide and not as the tautomeric hydroxy compound. The other theory suggests that Pauling intented to use the compound as a potential spectroscopic label for binding to DNA.

==References==

1. [http://www.arkat-usa.org/ARKIVOC/JOURNAL_CONTENT/manuscripts/2004/EM-917KP%20as%20published%20mainmanuscript.pdf "Theroetical study of cyameluric acid and related compounds"]

2. ''Proceedings of the National Academy of Sciences of the Untied States of America'', Vol. 23, No. 12, pp. 615-620 : '''The Structure of Cyameluric Acid, Hydromelonic Acid, and Related Substance''' - Linus Pauling; J. H. Sturdivant

3. [http://en.wikipedia.org/wiki/Melem''Melem'']

It:Cyameluric Acid

2006-12-06T15:44:08Z

Dh405: /* References */

{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
! {{chembox header}} colspan="3" |2D Structure of Cyanmeluric Acid
|-
| align="center" colspan="3" bgcolour="#ffffff" | [[Image:Cyanmeluric Acid jaa05.gif]]
|-
! {{chembox header}} colspan="3" |3D structure of Cyanmeluric Acid<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>
HEADER NONAME 20-Nov-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 20-Nov-06 0 NONE 4
ATOM 1 O 0 -1.758 -3.611 0.001 0.00 0.00 O-1
ATOM 2 C 0 -1.166 -2.396 0.001 0.00 0.00 C+0
ATOM 3 N 0 0.161 -2.322 0.000 0.00 0.00 N+0
ATOM 4 C 0 0.766 -1.134 0.000 0.00 0.00 C+0
ATOM 5 N 0 0.000 0.000 0.000 0.00 0.00 N+0
ATOM 6 N 0 2.094 -1.016 -0.000 0.00 0.00 N+0
ATOM 7 C 0 2.658 0.188 -0.000 0.00 0.00 C+0
ATOM 8 O 0 4.006 0.283 -0.000 0.00 0.00 O-1
ATOM 9 N 0 1.930 1.300 -0.000 0.00 0.00 N+0
ATOM 10 C 0 0.599 1.231 0.001 0.00 0.00 C+0
ATOM 11 N 0 -0.167 2.321 -0.000 0.00 0.00 N+0
ATOM 12 C 0 -1.492 2.208 0.001 0.00 0.00 C+0
ATOM 13 O 0 -2.248 3.328 -0.000 0.00 0.00 O-1
ATOM 14 N 0 -2.091 1.021 0.001 0.00 0.00 N+0
ATOM 15 C 0 -1.366 -0.097 0.000 0.00 0.00 C+0
ATOM 16 N 0 -1.927 -1.305 -0.004 0.00 0.00 N+0
CONECT 1 2 0 0 0 NONE 21
CONECT 2 1 16 3 0 NONE 22
CONECT 3 2 4 0 0 NONE 23
CONECT 4 3 5 6 0 NONE 24
CONECT 5 4 10 15 0 NONE 25
CONECT 6 4 7 0 0 NONE 26
CONECT 7 6 8 9 0 NONE 27
CONECT 8 7 0 0 0 NONE 28
CONECT 9 7 10 0 0 NONE 29
CONECT 10 9 5 11 0 NONE 30
CONECT 11 10 12 0 0 NONE 31
CONECT 12 11 13 14 0 NONE 32
CONECT 13 12 0 0 0 NONE 33
CONECT 14 12 15 0 0 NONE 34
CONECT 15 14 5 16 0 NONE 35
CONECT 16 15 2 0 0 NONE 36
END NONE 37
</inlineContents>
</jmolApplet>
</jmol>
|-
! {{chembox header}} colspan="3" | Properties
|-
| colspan="1" |IUPAC Systematic Name
| colspan="2"|
|-
| colspan="1" |CA Index Name
| colspan="2" |1,3,4,6,7,9,9b-Heptaazaphenalene-2,5,8(1H,3H,6H)
-trione, tripotassium salt, hydrate (9CI)
|-
| colspan="1" |Other Names
| colspan="2" |Cyameluric acid, tripotassium salt, hydrate
|-
| colspan="1" |Molecular formula
| colspan="2" |C6N7O33-
|-
| colspan="1" |SMILES String
| colspan="2" |[O-]C1=NC(N23)=NC([O-])=NC2=NC([O-])=NC3=N1
|-
| colspan="1" |Molecular Mass
| colspan="2" |218.11
|-
| colspan="1" |Appearance
| colspan="2" |
|-
|colspan="1" |Beilstein Registry number
| colspan="2" |3842474
|-
| colspan="1" |CAS Registry Number
| colspan="2" |42431-24-3
|-
| Melting Point
| colspan="2" |
|-
|colspan="1" |Boiling point
| colspan="2" |
|-
|colspan="1" |Refractive index
| colspan="2" |

|}

===History===
[[Image:Heptazines.bmp]]

The compound show above is called tri-s-triazine or 1,3,4,6,7,9,9b-Heptaazaphenalene or cyamelurine, if we change three R group with three amino substituents it is called melem. In Melon the heptazine is polymerized with the tri-s-triazine units linked through an amine (NH) link.

Derivate of heptazine with three hydroxyl substituents is called Cyameluric acid. The first person to suggest a structure for cyameluric acid is Josef Loschmidt, at 1861. His structure is in fact a meta-cyclophane, but this at a time when cyclic compounds of any type were not widely recognised.

==Discovery of Cyameluric acid==
In 1937 a structure of '''cyameluric acid''', C6N7(OH)3, was proposed by ''Pauling'' and ''Sturdivant''. The structure differed greatly from those of previous scientists. This type of molecule seemed to fascinate Pauling; the last thing he wrote on the chalkboard in his office before his death in 1994 was an azide derivative of cyameluric acid. It has been preserved there to this day by his friends.

In 1850 Henneberg prepared salts of the acid, and in 1933 Professor E. C. Franklin suggested the structure:

[[Image:Franklin.bmp]]

Franklin's research led Pauling and Sturdivant to similar formulations as studied by Franklin; hydromelonic acid is related to cyameluric acid as cyanuric tricyanamide is to cyanuric acid.

The Pauling/Sturdivant structure for cyameluric acid is made up of 3 coplanar rings fused together, with all angles approximately equal to 120°, the structure of the cyamelurate ion is shown in the table on the right. It is a delocalised system, and can be represented in a similar way to ''Kekule's'' structure for benzene, in a conjugated form:

[[Image:Resonance.bmp]]

Infinite structures can be formed in a hydrogen bonding network.

This proposed structure seems to hold the best explanation of properties of cyameluric acid. The resonance forms account for the high stability and the acid strength. This structure also corresponds to the hydrolysis porducts and is therefore the most likely structure. Although there is no report of the crystal structure of cyameluric acid to date.

As cyameluric acid has seventeen tautomers, which is the most stable one? DFT calculations (B3LYP/6-31G*) have been carried out on the these tautomers and find out the C3h trioxo tautomer 258 is the most stable. Some energies and absolute NMR shieldings (GIAO) were calculated for 258 and other tri-s-triazines, including cyamelurine and Pauling mystery molecule.

== Tips==
The heptazine derivate with an azide substituent and two hydroxyl groups is called Linus Pauling's mystery molecule. Two theories attempt to lift the mystery. It is suggested that Pauling failed to solve the double helix structure of DNA before Watson and Crick because he viewed uracil as an amide and not as the tautomeric hydroxy compound. The other theory suggests that Pauling intented to use the compound as a potential spectroscopic label for binding to DNA.

==References==

1. [http://www.arkat-usa.org/ARKIVOC/JOURNAL_CONTENT/manuscripts/2004/EM-917KP%20as%20published%20mainmanuscript.pdf "Theroetical study of cyameluric acid and related compounds"]

2. ''Proceedings of the National Academy of Sciences of the Untied States of America'', Vol. 23, No. 12, pp. 615-620 : '''The Structure of Cyameluric Acid, Hydromelonic Acid, and Related Substance''' - Linus Pauling; J. H. Sturdivant

3. [http://en.wikipedia.org/wiki/Melem]

It:Cyameluric Acid

2006-12-06T15:41:07Z

Dh405:

{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
! {{chembox header}} colspan="3" |2D Structure of Cyanmeluric Acid
|-
| align="center" colspan="3" bgcolour="#ffffff" | [[Image:Cyanmeluric Acid jaa05.gif]]
|-
! {{chembox header}} colspan="3" |3D structure of Cyanmeluric Acid<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>
HEADER NONAME 20-Nov-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 20-Nov-06 0 NONE 4
ATOM 1 O 0 -1.758 -3.611 0.001 0.00 0.00 O-1
ATOM 2 C 0 -1.166 -2.396 0.001 0.00 0.00 C+0
ATOM 3 N 0 0.161 -2.322 0.000 0.00 0.00 N+0
ATOM 4 C 0 0.766 -1.134 0.000 0.00 0.00 C+0
ATOM 5 N 0 0.000 0.000 0.000 0.00 0.00 N+0
ATOM 6 N 0 2.094 -1.016 -0.000 0.00 0.00 N+0
ATOM 7 C 0 2.658 0.188 -0.000 0.00 0.00 C+0
ATOM 8 O 0 4.006 0.283 -0.000 0.00 0.00 O-1
ATOM 9 N 0 1.930 1.300 -0.000 0.00 0.00 N+0
ATOM 10 C 0 0.599 1.231 0.001 0.00 0.00 C+0
ATOM 11 N 0 -0.167 2.321 -0.000 0.00 0.00 N+0
ATOM 12 C 0 -1.492 2.208 0.001 0.00 0.00 C+0
ATOM 13 O 0 -2.248 3.328 -0.000 0.00 0.00 O-1
ATOM 14 N 0 -2.091 1.021 0.001 0.00 0.00 N+0
ATOM 15 C 0 -1.366 -0.097 0.000 0.00 0.00 C+0
ATOM 16 N 0 -1.927 -1.305 -0.004 0.00 0.00 N+0
CONECT 1 2 0 0 0 NONE 21
CONECT 2 1 16 3 0 NONE 22
CONECT 3 2 4 0 0 NONE 23
CONECT 4 3 5 6 0 NONE 24
CONECT 5 4 10 15 0 NONE 25
CONECT 6 4 7 0 0 NONE 26
CONECT 7 6 8 9 0 NONE 27
CONECT 8 7 0 0 0 NONE 28
CONECT 9 7 10 0 0 NONE 29
CONECT 10 9 5 11 0 NONE 30
CONECT 11 10 12 0 0 NONE 31
CONECT 12 11 13 14 0 NONE 32
CONECT 13 12 0 0 0 NONE 33
CONECT 14 12 15 0 0 NONE 34
CONECT 15 14 5 16 0 NONE 35
CONECT 16 15 2 0 0 NONE 36
END NONE 37
</inlineContents>
</jmolApplet>
</jmol>
|-
! {{chembox header}} colspan="3" | Properties
|-
| colspan="1" |IUPAC Systematic Name
| colspan="2"|
|-
| colspan="1" |CA Index Name
| colspan="2" |1,3,4,6,7,9,9b-Heptaazaphenalene-2,5,8(1H,3H,6H)
-trione, tripotassium salt, hydrate (9CI)
|-
| colspan="1" |Other Names
| colspan="2" |Cyameluric acid, tripotassium salt, hydrate
|-
| colspan="1" |Molecular formula
| colspan="2" |C6N7O33-
|-
| colspan="1" |SMILES String
| colspan="2" |[O-]C1=NC(N23)=NC([O-])=NC2=NC([O-])=NC3=N1
|-
| colspan="1" |Molecular Mass
| colspan="2" |218.11
|-
| colspan="1" |Appearance
| colspan="2" |
|-
|colspan="1" |Beilstein Registry number
| colspan="2" |3842474
|-
| colspan="1" |CAS Registry Number
| colspan="2" |42431-24-3
|-
| Melting Point
| colspan="2" |
|-
|colspan="1" |Boiling point
| colspan="2" |
|-
|colspan="1" |Refractive index
| colspan="2" |

|}

===History===
[[Image:Heptazines.bmp]]

The compound show above is called tri-s-triazine or 1,3,4,6,7,9,9b-Heptaazaphenalene or cyamelurine, if we change three R group with three amino substituents it is called melem. In Melon the heptazine is polymerized with the tri-s-triazine units linked through an amine (NH) link.

Derivate of heptazine with three hydroxyl substituents is called Cyameluric acid. The first person to suggest a structure for cyameluric acid is Josef Loschmidt, at 1861. His structure is in fact a meta-cyclophane, but this at a time when cyclic compounds of any type were not widely recognised.

==Discovery of Cyameluric acid==
In 1937 a structure of '''cyameluric acid''', C6N7(OH)3, was proposed by ''Pauling'' and ''Sturdivant''. The structure differed greatly from those of previous scientists. This type of molecule seemed to fascinate Pauling; the last thing he wrote on the chalkboard in his office before his death in 1994 was an azide derivative of cyameluric acid. It has been preserved there to this day by his friends.

In 1850 Henneberg prepared salts of the acid, and in 1933 Professor E. C. Franklin suggested the structure:

[[Image:Franklin.bmp]]

Franklin's research led Pauling and Sturdivant to similar formulations as studied by Franklin; hydromelonic acid is related to cyameluric acid as cyanuric tricyanamide is to cyanuric acid.

The Pauling/Sturdivant structure for cyameluric acid is made up of 3 coplanar rings fused together, with all angles approximately equal to 120°, the structure of the cyamelurate ion is shown in the table on the right. It is a delocalised system, and can be represented in a similar way to ''Kekule's'' structure for benzene, in a conjugated form:

[[Image:Resonance.bmp]]

Infinite structures can be formed in a hydrogen bonding network.

This proposed structure seems to hold the best explanation of properties of cyameluric acid. The resonance forms account for the high stability and the acid strength. This structure also corresponds to the hydrolysis porducts and is therefore the most likely structure. Although there is no report of the crystal structure of cyameluric acid to date.

As cyameluric acid has seventeen tautomers, which is the most stable one? DFT calculations (B3LYP/6-31G*) have been carried out on the these tautomers and find out the C3h trioxo tautomer 258 is the most stable. Some energies and absolute NMR shieldings (GIAO) were calculated for 258 and other tri-s-triazines, including cyamelurine and Pauling mystery molecule.

== Tips==
The heptazine derivate with an azide substituent and two hydroxyl groups is called Linus Pauling's mystery molecule. Two theories attempt to lift the mystery. It is suggested that Pauling failed to solve the double helix structure of DNA before Watson and Crick because he viewed uracil as an amide and not as the tautomeric hydroxy compound. The other theory suggests that Pauling intented to use the compound as a potential spectroscopic label for binding to DNA.

==References==

1. [http://www.arkat-usa.org/ARKIVOC/JOURNAL_CONTENT/manuscripts/2004/EM-917KP%20as%20published%20mainmanuscript.pdf "Theroetical study of cyameluric acid and related compounds"]

2. ''Proceedings of the National Academy of Sciences of the Untied States of America'', Vol. 23, No. 12, pp. 615-620 : '''The Structure of Cyameluric Acid, Hydromelonic Acid, and Related Substance''' - Linus Pauling; J. H. Sturdivant

It:Cyameluric Acid

2006-12-06T15:20:52Z

Dh405: /* History */

{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
! {{chembox header}} colspan="3" |2D Structure of Cyanmeluric Acid
|-
| align="center" colspan="3" bgcolour="#ffffff" | [[Image:Cyanmeluric Acid jaa05.gif]]
|-
! {{chembox header}} colspan="3" |3D structure of Cyanmeluric Acid<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>
HEADER NONAME 20-Nov-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 20-Nov-06 0 NONE 4
ATOM 1 O 0 -1.758 -3.611 0.001 0.00 0.00 O-1
ATOM 2 C 0 -1.166 -2.396 0.001 0.00 0.00 C+0
ATOM 3 N 0 0.161 -2.322 0.000 0.00 0.00 N+0
ATOM 4 C 0 0.766 -1.134 0.000 0.00 0.00 C+0
ATOM 5 N 0 0.000 0.000 0.000 0.00 0.00 N+0
ATOM 6 N 0 2.094 -1.016 -0.000 0.00 0.00 N+0
ATOM 7 C 0 2.658 0.188 -0.000 0.00 0.00 C+0
ATOM 8 O 0 4.006 0.283 -0.000 0.00 0.00 O-1
ATOM 9 N 0 1.930 1.300 -0.000 0.00 0.00 N+0
ATOM 10 C 0 0.599 1.231 0.001 0.00 0.00 C+0
ATOM 11 N 0 -0.167 2.321 -0.000 0.00 0.00 N+0
ATOM 12 C 0 -1.492 2.208 0.001 0.00 0.00 C+0
ATOM 13 O 0 -2.248 3.328 -0.000 0.00 0.00 O-1
ATOM 14 N 0 -2.091 1.021 0.001 0.00 0.00 N+0
ATOM 15 C 0 -1.366 -0.097 0.000 0.00 0.00 C+0
ATOM 16 N 0 -1.927 -1.305 -0.004 0.00 0.00 N+0
CONECT 1 2 0 0 0 NONE 21
CONECT 2 1 16 3 0 NONE 22
CONECT 3 2 4 0 0 NONE 23
CONECT 4 3 5 6 0 NONE 24
CONECT 5 4 10 15 0 NONE 25
CONECT 6 4 7 0 0 NONE 26
CONECT 7 6 8 9 0 NONE 27
CONECT 8 7 0 0 0 NONE 28
CONECT 9 7 10 0 0 NONE 29
CONECT 10 9 5 11 0 NONE 30
CONECT 11 10 12 0 0 NONE 31
CONECT 12 11 13 14 0 NONE 32
CONECT 13 12 0 0 0 NONE 33
CONECT 14 12 15 0 0 NONE 34
CONECT 15 14 5 16 0 NONE 35
CONECT 16 15 2 0 0 NONE 36
END NONE 37
</inlineContents>
</jmolApplet>
</jmol>
|-
! {{chembox header}} colspan="3" | Properties
|-
| colspan="1" |IUPAC Systematic Name
| colspan="2"|
|-
| colspan="1" |Molecular formula
| colspan="2" |C6N7O33-
|-
| colspan="1" |SMILES String
| colspan="2" |[O-]C1=NC(N23)=NC([O-])=NC2=NC([O-])=NC3=N1
|-
| colspan="1" |Molecular Mass
| colspan="2" |218.11
|-
| colspan="1" |Appearance
| colspan="2" |
|-
|colspan="1" |Beilstein Registry number
| colspan="2" |3842474
|-
| colspan="1" |CAS Registry Number
| colspan="2" |42431-24-3
|-
| Melting Point
| colspan="2" |
|-
|colspan="1" |Boiling point
| colspan="2" |
|-
|colspan="1" |Refractive index
| colspan="2" |

|}

===History===
[[Image:Heptazines.bmp]]

The compound show above is called tri-s-triazine or 1,3,4,6,7,9,9b-Heptaazaphenalene or cyamelurine, if we change three R group with three amino substituents it is called melem. In Melon the heptazine is polymerized with the tri-s-triazine units linked through an amine (NH) link.

Derivate of heptazine with three hydroxyl substituents is called Cyameluric acid. The first person to suggest a structure for cyameluric acid is Josef Loschmidt, at 1861. His structure is in fact a meta-cyclophane, but this at a time when cyclic compounds of any type were not widely recognised.

==Discovery of Cyameluric acid==
In 1937 a structure of '''cyameluric acid''', C6N7(OH)3, was proposed by ''Pauling'' and ''Sturdivant''. The structure differed greatly from those of previous scientists. This type of molecule seemed to fascinate Pauling; the last thing he wrote on the chalkboard in his office before his death in 1994 was an azide derivative of cyameluric acid. It has been preserved there to this day by his friends.

In 1850 Henneberg prepared salts of the acid, and in 1933 Professor E. C. Franklin suggested the structure:

[[Image:Franklin.bmp]]

Franklin's research led Pauling and Sturdivant to similar formulations as studied by Franklin; hydromelonic acid is related to cyameluric acid as cyanuric tricyanamide is to cyanuric acid.

The Pauling/Sturdivant structure for cyameluric acid is made up of 3 coplanar rings fused together, with all angles approximately equal to 120°, the structure of the cyamelurate ion is shown in the table on the right. It is a delocalised system, and can be represented in a similar way to ''Kekule's'' structure for benzene, in a conjugated form:

[[Image:Resonance.bmp]]

Infinite structures can be formed in a hydrogen bonding network.

This proposed structure seems to hold the best explanation of properties of cyameluric acid. The resonance forms account for the high stability and the acid strength. This structure also corresponds to the hydrolysis porducts and is therefore the most likely structure. Although there is no report of the crystal structure of cyameluric acid to date.

As cyameluric acid has seventeen tautomers, which is the most stable one? DFT calculations (B3LYP/6-31G*) have been carried out on the these tautomers and find out the C3h trioxo tautomer 258 is the most stable. Some energies and absolute NMR shieldings (GIAO) were calculated for 258 and other tri-s-triazines, including cyamelurine and Pauling mystery molecule.

== Tips==
The heptazine derivate with an azide substituent and two hydroxyl groups is called Linus Pauling's mystery molecule. Two theories attempt to lift the mystery. It is suggested that Pauling failed to solve the double helix structure of DNA before Watson and Crick because he viewed uracil as an amide and not as the tautomeric hydroxy compound. The other theory suggests that Pauling intented to use the compound as a potential spectroscopic label for binding to DNA.

==References==

1. [http://www.arkat-usa.org/ARKIVOC/JOURNAL_CONTENT/manuscripts/2004/EM-917KP%20as%20published%20mainmanuscript.pdf "Theroetical study of cyameluric acid and related compounds"]

2. ''Proceedings of the National Academy of Sciences of the Untied States of America'', Vol. 23, No. 12, pp. 615-620 : '''The Structure of Cyameluric Acid, Hydromelonic Acid, and Related Substance''' - Linus Pauling; J. H. Sturdivant

It:Cyameluric Acid

2006-12-06T15:12:00Z

Dh405: /* Discovery of Cyameluric acid */

{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
! {{chembox header}} colspan="3" |2D Structure of Cyanmeluric Acid
|-
| align="center" colspan="3" bgcolour="#ffffff" | [[Image:Cyanmeluric Acid jaa05.gif]]
|-
! {{chembox header}} colspan="3" |3D structure of Cyanmeluric Acid<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>
HEADER NONAME 20-Nov-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 20-Nov-06 0 NONE 4
ATOM 1 O 0 -1.758 -3.611 0.001 0.00 0.00 O-1
ATOM 2 C 0 -1.166 -2.396 0.001 0.00 0.00 C+0
ATOM 3 N 0 0.161 -2.322 0.000 0.00 0.00 N+0
ATOM 4 C 0 0.766 -1.134 0.000 0.00 0.00 C+0
ATOM 5 N 0 0.000 0.000 0.000 0.00 0.00 N+0
ATOM 6 N 0 2.094 -1.016 -0.000 0.00 0.00 N+0
ATOM 7 C 0 2.658 0.188 -0.000 0.00 0.00 C+0
ATOM 8 O 0 4.006 0.283 -0.000 0.00 0.00 O-1
ATOM 9 N 0 1.930 1.300 -0.000 0.00 0.00 N+0
ATOM 10 C 0 0.599 1.231 0.001 0.00 0.00 C+0
ATOM 11 N 0 -0.167 2.321 -0.000 0.00 0.00 N+0
ATOM 12 C 0 -1.492 2.208 0.001 0.00 0.00 C+0
ATOM 13 O 0 -2.248 3.328 -0.000 0.00 0.00 O-1
ATOM 14 N 0 -2.091 1.021 0.001 0.00 0.00 N+0
ATOM 15 C 0 -1.366 -0.097 0.000 0.00 0.00 C+0
ATOM 16 N 0 -1.927 -1.305 -0.004 0.00 0.00 N+0
CONECT 1 2 0 0 0 NONE 21
CONECT 2 1 16 3 0 NONE 22
CONECT 3 2 4 0 0 NONE 23
CONECT 4 3 5 6 0 NONE 24
CONECT 5 4 10 15 0 NONE 25
CONECT 6 4 7 0 0 NONE 26
CONECT 7 6 8 9 0 NONE 27
CONECT 8 7 0 0 0 NONE 28
CONECT 9 7 10 0 0 NONE 29
CONECT 10 9 5 11 0 NONE 30
CONECT 11 10 12 0 0 NONE 31
CONECT 12 11 13 14 0 NONE 32
CONECT 13 12 0 0 0 NONE 33
CONECT 14 12 15 0 0 NONE 34
CONECT 15 14 5 16 0 NONE 35
CONECT 16 15 2 0 0 NONE 36
END NONE 37
</inlineContents>
</jmolApplet>
</jmol>
|-
! {{chembox header}} colspan="3" | Properties
|-
| colspan="1" |IUPAC Systematic Name
| colspan="2"|
|-
| colspan="1" |Molecular formula
| colspan="2" |C6N7O33-
|-
| colspan="1" |SMILES String
| colspan="2" |[O-]C1=NC(N23)=NC([O-])=NC2=NC([O-])=NC3=N1
|-
| colspan="1" |Molecular Mass
| colspan="2" |218.11
|-
| colspan="1" |Appearance
| colspan="2" |
|-
|colspan="1" |Beilstein Registry number
| colspan="2" |3842474
|-
| colspan="1" |CAS Registry Number
| colspan="2" |42431-24-3
|-
| Melting Point
| colspan="2" |
|-
|colspan="1" |Boiling point
| colspan="2" |
|-
|colspan="1" |Refractive index
| colspan="2" |

|}

===History===
[[Image:Heptazines.bmp]]

The compound showed above is called tri-s-triazine or 1,3,4,6,7,9,9b-Heptaazaphenalene or cyamelurine, if we change three R group with three amino substituents it is called melem. In Melon the heptazine is polymerized with the tri-s-triazine units linked through an amine (NH) link.

Cyameluric acid is the heptazine derivate with three hydroxyl substituents, it has many possible tautomeric structures. Of the seventeen tautomeric forms, this compound is not a hydroxide but an amide as calculations showed that of the tri-oxo forms was found to be the most stable. The first person to suggest a structure for cyameluric acid was Josef Loschmidt, as far back as 1861. His structure was in fact a meta-cyclophane, but this at a time when cyclic compounds of any type were not widely recognised.

==Discovery of Cyameluric acid==
In 1937 a structure of '''cyameluric acid''', C6N7(OH)3, was proposed by ''Pauling'' and ''Sturdivant''. The structure differed greatly from those of previous scientists. This type of molecule seemed to fascinate Pauling; the last thing he wrote on the chalkboard in his office before his death in 1994 was an azide derivative of cyameluric acid. It has been preserved there to this day by his friends.

In 1850 Henneberg prepared salts of the acid, and in 1933 Professor E. C. Franklin suggested the structure:

[[Image:Franklin.bmp]]

Franklin's research led Pauling and Sturdivant to similar formulations as studied by Franklin; hydromelonic acid is related to cyameluric acid as cyanuric tricyanamide is to cyanuric acid.

The Pauling/Sturdivant structure for cyameluric acid is made up of 3 coplanar rings fused together, with all angles approximately equal to 120°, the structure of the cyamelurate ion is shown in the table on the right. It is a delocalised system, and can be represented in a similar way to ''Kekule's'' structure for benzene, in a conjugated form:

[[Image:Resonance.bmp]]

Infinite structures can be formed in a hydrogen bonding network.

This proposed structure seems to hold the best explanation of properties of cyameluric acid. The resonance forms account for the high stability and the acid strength. This structure also corresponds to the hydrolysis porducts and is therefore the most likely structure. Although there is no report of the crystal structure of cyameluric acid to date.

As cyameluric acid has seventeen tautomers, which is the most stable one? DFT calculations (B3LYP/6-31G*) have been carried out on the these tautomers and find out the C3h trioxo tautomer 258 is the most stable. Some energies and absolute NMR shieldings (GIAO) were calculated for 258 and other tri-s-triazines, including cyamelurine and Pauling mystery molecule.

== Tips==
The heptazine derivate with an azide substituent and two hydroxyl groups is called Linus Pauling's mystery molecule. Two theories attempt to lift the mystery. It is suggested that Pauling failed to solve the double helix structure of DNA before Watson and Crick because he viewed uracil as an amide and not as the tautomeric hydroxy compound. The other theory suggests that Pauling intented to use the compound as a potential spectroscopic label for binding to DNA.

==References==

1. [http://www.arkat-usa.org/ARKIVOC/JOURNAL_CONTENT/manuscripts/2004/EM-917KP%20as%20published%20mainmanuscript.pdf "Theroetical study of cyameluric acid and related compounds"]

It:Cyameluric Acid

2006-12-06T14:58:40Z

Dh405: /* History */

{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
! {{chembox header}} colspan="3" |2D Structure of Cyanmeluric Acid
|-
| align="center" colspan="3" bgcolour="#ffffff" | [[Image:Cyanmeluric Acid jaa05.gif]]
|-
! {{chembox header}} colspan="3" |3D structure of Cyanmeluric Acid<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>
HEADER NONAME 20-Nov-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 20-Nov-06 0 NONE 4
ATOM 1 O 0 -1.758 -3.611 0.001 0.00 0.00 O-1
ATOM 2 C 0 -1.166 -2.396 0.001 0.00 0.00 C+0
ATOM 3 N 0 0.161 -2.322 0.000 0.00 0.00 N+0
ATOM 4 C 0 0.766 -1.134 0.000 0.00 0.00 C+0
ATOM 5 N 0 0.000 0.000 0.000 0.00 0.00 N+0
ATOM 6 N 0 2.094 -1.016 -0.000 0.00 0.00 N+0
ATOM 7 C 0 2.658 0.188 -0.000 0.00 0.00 C+0
ATOM 8 O 0 4.006 0.283 -0.000 0.00 0.00 O-1
ATOM 9 N 0 1.930 1.300 -0.000 0.00 0.00 N+0
ATOM 10 C 0 0.599 1.231 0.001 0.00 0.00 C+0
ATOM 11 N 0 -0.167 2.321 -0.000 0.00 0.00 N+0
ATOM 12 C 0 -1.492 2.208 0.001 0.00 0.00 C+0
ATOM 13 O 0 -2.248 3.328 -0.000 0.00 0.00 O-1
ATOM 14 N 0 -2.091 1.021 0.001 0.00 0.00 N+0
ATOM 15 C 0 -1.366 -0.097 0.000 0.00 0.00 C+0
ATOM 16 N 0 -1.927 -1.305 -0.004 0.00 0.00 N+0
CONECT 1 2 0 0 0 NONE 21
CONECT 2 1 16 3 0 NONE 22
CONECT 3 2 4 0 0 NONE 23
CONECT 4 3 5 6 0 NONE 24
CONECT 5 4 10 15 0 NONE 25
CONECT 6 4 7 0 0 NONE 26
CONECT 7 6 8 9 0 NONE 27
CONECT 8 7 0 0 0 NONE 28
CONECT 9 7 10 0 0 NONE 29
CONECT 10 9 5 11 0 NONE 30
CONECT 11 10 12 0 0 NONE 31
CONECT 12 11 13 14 0 NONE 32
CONECT 13 12 0 0 0 NONE 33
CONECT 14 12 15 0 0 NONE 34
CONECT 15 14 5 16 0 NONE 35
CONECT 16 15 2 0 0 NONE 36
END NONE 37
</inlineContents>
</jmolApplet>
</jmol>
|-
! {{chembox header}} colspan="3" | Properties
|-
| colspan="1" |IUPAC Systematic Name
| colspan="2"|
|-
| colspan="1" |Molecular formula
| colspan="2" |C6N7O33-
|-
| colspan="1" |SMILES String
| colspan="2" |[O-]C1=NC(N23)=NC([O-])=NC2=NC([O-])=NC3=N1
|-
| colspan="1" |Molecular Mass
| colspan="2" |218.11
|-
| colspan="1" |Appearance
| colspan="2" |
|-
|colspan="1" |Beilstein Registry number
| colspan="2" |3842474
|-
| colspan="1" |CAS Registry Number
| colspan="2" |42431-24-3
|-
| Melting Point
| colspan="2" |
|-
|colspan="1" |Boiling point
| colspan="2" |
|-
|colspan="1" |Refractive index
| colspan="2" |

|}

===History===
[[Image:Heptazines.bmp]]

The compound showed above is called tri-s-triazine or 1,3,4,6,7,9,9b-Heptaazaphenalene or cyamelurine, if we change three R group with three amino substituents it is called melem. In Melon the heptazine is polymerized with the tri-s-triazine units linked through an amine (NH) link.

Cyameluric acid is the heptazine derivate with three hydroxyl substituents, it has many possible tautomeric structures. Of the seventeen tautomeric forms, this compound is not a hydroxide but an amide as calculations showed that of the tri-oxo forms was found to be the most stable. The first person to suggest a structure for cyameluric acid was Josef Loschmidt, as far back as 1861. His structure was in fact a meta-cyclophane, but this at a time when cyclic compounds of any type were not widely recognised.

==Discovery of Cyameluric acid==
In 1937 a structure of '''cyameluric acid''', C6N7(OH)3, was proposed by ''Pauling'' and ''Sturdivant''. The structure differed greatly from those of previous scientists. This type of molecule seemed to fascinate Pauling; the last thing he wrote on the chalkboard in his office before his death in 1994 was an azide derivative of cyameluric acid. It has been preserved there to this day by his friends.

In 1850 Henneberg prepared salts of the acid, and in 1933 Professor E. C. Franklin suggested the structure:

[[Image:Franklin.bmp]]

Franklin's research led Pauling and Sturdivant to similar formulations as studied by Franklin; hydromelonic acid is related to cyameluric acid as cyanuric tricyanamide is to cyanuric acid.

The Pauling/Sturdivant structure for cyameluric acid is made up of 3 coplanar rings fused together, with all angles approximately equal to 120°, the structure of the cyamelurate ion is shown in the table on the right. It is a delocalised system, and can be represented in a similar way to ''Kekule's'' structure for benzene, in a conjugated form:

[[Image:Resonance.bmp]]

Infinite structures can be formed in a hydrogen bonding network.

This proposed structure seems to hold the best explanation of properties of cyameluric acid. The resonance forms account for the high stability and the acid strength. This structure also corresponds to the hydrolysis porducts and is therefore the most likely structure. Although there is no report of the crystal structure of cyameluric acid to date.

== Tips==
The heptazine derivate with an azide substituent and two hydroxyl groups is called Linus Pauling's mystery molecule. Two theories attempt to lift the mystery. It is suggested that Pauling failed to solve the double helix structure of DNA before Watson and Crick because he viewed uracil as an amide and not as the tautomeric hydroxy compound. The other theory suggests that Pauling intented to use the compound as a potential spectroscopic label for binding to DNA.

==References==

1. [http://www.arkat-usa.org/ARKIVOC/JOURNAL_CONTENT/manuscripts/2004/EM-917KP%20as%20published%20mainmanuscript.pdf "Theroetical study of cyameluric acid and related compounds"]

It:Cyameluric Acid

2006-12-06T14:49:59Z

Dh405: /* History */

{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"
! {{chembox header}} colspan="3" |2D Structure of Cyanmeluric Acid
|-
| align="center" colspan="3" bgcolour="#ffffff" | [[Image:Cyanmeluric Acid jaa05.gif]]
|-
! {{chembox header}} colspan="3" |3D structure of Cyanmeluric Acid<jmol>
<jmolApplet>
<size>200</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>
HEADER NONAME 20-Nov-06 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 20-Nov-06 0 NONE 4
ATOM 1 O 0 -1.758 -3.611 0.001 0.00 0.00 O-1
ATOM 2 C 0 -1.166 -2.396 0.001 0.00 0.00 C+0
ATOM 3 N 0 0.161 -2.322 0.000 0.00 0.00 N+0
ATOM 4 C 0 0.766 -1.134 0.000 0.00 0.00 C+0
ATOM 5 N 0 0.000 0.000 0.000 0.00 0.00 N+0
ATOM 6 N 0 2.094 -1.016 -0.000 0.00 0.00 N+0
ATOM 7 C 0 2.658 0.188 -0.000 0.00 0.00 C+0
ATOM 8 O 0 4.006 0.283 -0.000 0.00 0.00 O-1
ATOM 9 N 0 1.930 1.300 -0.000 0.00 0.00 N+0
ATOM 10 C 0 0.599 1.231 0.001 0.00 0.00 C+0
ATOM 11 N 0 -0.167 2.321 -0.000 0.00 0.00 N+0
ATOM 12 C 0 -1.492 2.208 0.001 0.00 0.00 C+0
ATOM 13 O 0 -2.248 3.328 -0.000 0.00 0.00 O-1
ATOM 14 N 0 -2.091 1.021 0.001 0.00 0.00 N+0
ATOM 15 C 0 -1.366 -0.097 0.000 0.00 0.00 C+0
ATOM 16 N 0 -1.927 -1.305 -0.004 0.00 0.00 N+0
CONECT 1 2 0 0 0 NONE 21
CONECT 2 1 16 3 0 NONE 22
CONECT 3 2 4 0 0 NONE 23
CONECT 4 3 5 6 0 NONE 24
CONECT 5 4 10 15 0 NONE 25
CONECT 6 4 7 0 0 NONE 26
CONECT 7 6 8 9 0 NONE 27
CONECT 8 7 0 0 0 NONE 28
CONECT 9 7 10 0 0 NONE 29
CONECT 10 9 5 11 0 NONE 30
CONECT 11 10 12 0 0 NONE 31
CONECT 12 11 13 14 0 NONE 32
CONECT 13 12 0 0 0 NONE 33
CONECT 14 12 15 0 0 NONE 34
CONECT 15 14 5 16 0 NONE 35
CONECT 16 15 2 0 0 NONE 36
END NONE 37
</inlineContents>
</jmolApplet>
</jmol>
|-
! {{chembox header}} colspan="3" | Properties
|-
| colspan="1" |IUPAC Systematic Name
| colspan="2"|
|-
| colspan="1" |Molecular formula
| colspan="2" |C6N7O33-
|-
| colspan="1" |SMILES String
| colspan="2" |[O-]C1=NC(N23)=NC([O-])=NC2=NC([O-])=NC3=N1
|-
| colspan="1" |Molecular Mass
| colspan="2" |218.11
|-
| colspan="1" |Appearance
| colspan="2" |
|-
|colspan="1" |Beilstein Registry number
| colspan="2" |3842474
|-
| colspan="1" |CAS Registry Number
| colspan="2" |42431-24-3
|-
| Melting Point
| colspan="2" |
|-
|colspan="1" |Boiling point
| colspan="2" |
|-
|colspan="1" |Refractive index
| colspan="2" |

|}

===History===
[[Image:Heptazines.bmp]]

The compound showed above is called tri-s-triazine or 1,3,4,6,7,9,9b-Heptaazaphenalene or cyamelurine, if we change three R group with three amino substituents it is called melem. In Melon the heptazine is polymerized with the tri-s-triazine units linked through an amine (NH) link.

Cyameluric acid is the heptazine derivate with three hydroxyl substituents, it has many possible tautomeric structures. Of the seventeen tautomeric forms, this compound is not a hydroxide but an amide as calculations showed that of the tri-oxo forms was found to be the most stable. The first person to suggest a structure for cyameluric acid was Josef Loschmidt, as far back as 1861. His structure was in fact a meta-cyclophane, but this at a time when cyclic compounds of any type were not widely recognised.

In 1937 a structure of '''cyameluric acid''', C6N7(OH)3, was proposed by ''Pauling'' and ''Sturdivant''. The structure differed greatly from those of previous scientists. This type of molecule seemed to fascinate Pauling; the last thing he wrote on the chalkboard in his office before his death in 1994 was an azide derivative of cyameluric acid. It has been preserved there to this day by his friends.

In 1850 Henneberg prepared salts of the acid, and in 1933 Professor E. C. Franklin suggested the structure:

[[Image:Franklin.bmp]]

Franklin's research led Pauling and Sturdivant to similar formulations as studied by Franklin; hydromelonic acid is related to cyameluric acid as cyanuric tricyanamide is to cyanuric acid.

The Pauling/Sturdivant structure for cyameluric acid is made up of 3 coplanar rings fused together, with all angles approximately equal to 120°, the structure of the cyamelurate ion is shown in the table on the right. It is a delocalised system, and can be represented in a similar way to ''Kekule's'' structure for benzene, in a conjugated form:

[[Image:Resonance.bmp]]

Infinite structures can be formed in a hydrogen bonding network.

This proposed structure seems to hold the best explanation of properties of cyameluric acid. The resonance forms account for the high stability and the acid strength. This structure also corresponds to the hydrolysis porducts and is therefore the most likely structure. Although there is no report of the crystal structure of cyameluric acid to date.

== Tips==
The heptazine derivate with an azide substituent and two hydroxyl groups is called Linus Pauling's mystery molecule. Two theories attempt to lift the mystery. It is suggested that Pauling failed to solve the double helix structure of DNA before Watson and Crick because he viewed uracil as an amide and not as the tautomeric hydroxy compound. The other theory suggests that Pauling intented to use the compound as a potential spectroscopic label for binding to DNA.

==References==

1. [http://www.arkat-usa.org/ARKIVOC/JOURNAL_CONTENT/manuscripts/2004/EM-917KP%20as%20published%20mainmanuscript.pdf "Theroetical study of cyameluric acid and related compounds"]

File:Heptazines.bmp

2006-12-06T14:33:58Z

Dh405: by Tina Han

by Tina Han

File:Dichlorodifluoromethane

2006-12-06T14:27:12Z

Dh405: by Tina Han

by Tina Han

It:projects

2006-12-06T12:33:07Z

Dh405: /* Supplemental Project Page */

__FORCETOC__

'''''You MUST use the Edit buttons on the right to edit this content. Do NOT use the Edit button on the top of this page.'''''
== Sandbox (Play-Pen) ==

This is an area where you can play without worrying what you do. Enter it by pressing the [Edit] button '''on the right''' and '''not''' at the top. Go here for a [http://en.wikipedia.org/wiki/Wikipedia:Cheatsheet ''cheat sheet''] summary of how to create a Wiki page. It's a free-for-all in here! Learn how to use a Wiki by coming here! PS This is how to do Greek: Α, α, β Δ, δ
Try copying/pasting some of the [http://www.ch.ic.ac.uk/local/it/lab1.html examples in the course work] into this page. See the effect by selecting '''Show Preview'''. No not use '''Save Page''' so as to leave this area uncluttered for others.
----
{|
|NEW: This demonstrates the use of Jmol loading discrete molecule files (rather than having to paste them into the wiki page). Upload the molecule file, and invoke it as shown here. Use it for eg loading large proteins etc. Sorry about the delay in getting this working, but the cause was pretty unobvious.--[[User:Rzepa|Rzepa]] 16:07, 4 December 2006 (UTC)
<center><jmol>
<jmolApplet>
<title>Pentahelicene</title><color>yellow</color>
<uploadedFileContents>Pentahelicene.mol</uploadedFileContents>
</jmolApplet>
<jmolMenu>
<item><text>Start spinning</text><script>spin on</script></item>
<item><text>Stop spinning</text><script>spin off</script></item>
<menuHeight>-1</menuHeight>
</jmolMenu>
<jmolButton>
<script>console</script>
<text>open a console window</text>
</jmolButton>
</jmol></center>
-----
<center><jmol><jmolAppletButton><title>Show Pentahelicene in popup window</title><color>cyan</color>
<uploadedFileContents>Pentahelicene.mol</uploadedFileContents></jmolAppletButton>
</jmol></center>

== Main Project Page ==
'''Please do not edit this page itself'''. Click on one of the titles to start editing.
{| summary="CIT Project Titles" border="1"
! bgcolor="cyan" |Project Number
! bgcolor="cyan" |General Keywords
|-
| bgcolor="#CCFF00" |01
| bgcolor="#CCFF00" | [[it:Lignocaine|Lignocaine (used in dentistry as a "local")]]
|-
| bgcolor="#CCFF00" |02
| bgcolor="#66FF99" | [[it:Piperine|Piperine (active ingredient of both black and white pepper)]]
|-
| bgcolor="#CCFF00" |03
| bgcolor="#CCFF00" | [[it:Rapamycin|Rapamycin (prevents transplant rejection)]]
|-
| bgcolor="#CCFF00" |04
| bgcolor="#66FF99" | [[it:Gossypol|Gossypol (male birth control)]]
|-
| bgcolor="#CCFF00" |05
| bgcolor="#CCFF00" | [[it:Gentamycin|Gentamicin A (aminoglycoside antibiotic)]]
|-
| bgcolor="#CCFF00" |06
| bgcolor="#66FF99" | [[it:Herceptin|Herceptin (topical anticancer drug)]]
|-
| bgcolor="#CCFF00" |07
| bgcolor="#CCFF00" | [[it:Gingerone|Zingerone (the characteristic smell of ginger)]]
|-
| bgcolor="#CCFF00" |08
| bgcolor="#66FF99" | [[it:Sucralose|Sucralose (non-metabolizable sweetening agent)]]
|-
| bgcolor="#CCFF00" |09
| bgcolor="#CCFF00" | [[it:Bufotoxin|Bufotoxin (active component of the toad ''Bufo vulgaris'')]]
|-
| bgcolor="#CCFF00" |10
| bgcolor="#66FF99" | [[it:Roaccutane|Roaccutane (treatment for severe acne)]]
|-
| bgcolor="#CCFF00" |11
| bgcolor="#CCFF00" | [[it:Sibutramine|Sibutramine (appetite suppresor)]]
|-
| bgcolor="#CCFF00" |12
| bgcolor="#66FF99" | [[it:Anandamide|Anandamide (the "feel-good" factor in chocolate)]]
|-
| bgcolor="#CCFF00" |13
| bgcolor="#CCFF00" | [[it:h3nbh3|Ammonia-borane: H3N-BH3 (Hydrogen storage molecule?)]]
|-
| bgcolor="#CCFF00" |14
| bgcolor="#66FF99" | [[it:Methoxsalen|Methoxsalen (Treatment of psoriasis)]]
|-
| bgcolor="#CCFF00" |15
| bgcolor="#CCFF00" | [[it:Hycocine|Hyoscine (From Mandrake and Witches Henbane, pre-med before surgery)]]
|-
| bgcolor="#CCFF00" |16
| bgcolor="#66FF99" | [[it:Capreomycin|Capreomycin (Drug-resistant TB)]]
|-
| bgcolor="#CCFF00" |17
| bgcolor="#CCFF00" | [[it:wilkinson|Wilkinson's catalyst]]
|-
| bgcolor="#CCFF00" |18
| bgcolor="#66FF99" | [[it:Jacobsen|Jacobsen's epoxidation catalyst]]
|-
| bgcolor="#CCFF00" |19
| bgcolor="#CCFF00" | [[it:Methylaluminoxane|Methylaluminoxane: MAO - hugely important ethylene polymerisation cocatalyst]]
|-
| bgcolor="#CCFF00" |20
| bgcolor="#66FF99" | [[it:Schwartz|Schwartz reagent for the hydrozirconation of alkenes and alkynes]]
|-
| bgcolor="#CCFF00" |21
| bgcolor="#CCFF00" | [[it:Schrock|Schrock metathesis catalyst]]
|-
| bgcolor="#CCFF00" |22
| bgcolor="#66FF99" | [[it:knots|Molecular-scale knots (nanoscale devices)]]
|-
|bgcolor="#CCFF00" |23
| bgcolor="#CCFF00" | [[it:Vioxx|Vioxx (treatment of osteoarthritis symptoms and pain)]]
|-
| bgcolor="#CCFF00" |24
| bgcolor="#66FF99" | [[it:Sertraline|Sertraline HCl (anti-depression)]]
|-
| bgcolor="#CCFF00" |25
| bgcolor="#CCFF00" | [[it:Ceftriaxone|Ceftriaxone (Gonorrhoea)]]
|-
| bgcolor="#CCFF00" |26
| bgcolor="#66FF99" | [[it:Zithromycin|Zithromycin (anti-infective)]]
|-
| bgcolor="#CCFF00" |27
| bgcolor="#CCFF00" | [[it:Lipitor|Lipitor (Cholesterol reducing agent)]]
|-
| bgcolor="#CCFF00" |28
| bgcolor="#66FF99" | [[it:Cyameluric Acid|Cyameluric acid (Linus Pauling's last idea!)]]
|}

== Supplemental Project Page ==

This area is for people who wish to create their own projects if none of the above appeal to them. Click on the '''Edit''' button to the right to open up an editable page,
then add an entry below as follows

*<nowiki> [[it:name_of_project|Descriptive name of intended project]]</nowiki>
*This will produce the effect: [[it:name_of_project|Descriptive name of intended project]]
----
*[[it:sitagliptin_page|Sitagliptin]]
*[[it:Retinal|Retinal, molecule of sight]]
*[[it:Tamoxifen|Tamoxifen, breast cancer treatment]]
*[[it:Morphine|Morphine, painkiller]]
*[[it:Pelargonidin|Pelargonidin, colouring in nature]]
*[[it:Propanil|Propanil, weedkiller]]
*[[it:Ranitidine|Ranitidine, antiulcerative]]
*[[it:chlorphentermine|chlorphentermine, anorectic]]
*[[it:Serotonin|Serotonin, The 'HAPPY' Drug]]
*[[it:Amphidinolide T1|Amphidinolide T1]]
*[[it:Rosiglitazone|Rosiglitazone, drug that is currently used to treat diabetes.]]
*[[it:Furosemide|Furosemide]]
*[[it:Tryptophan|Tryptophan]]
*[[it:methylpentynol|methylpentynol, tranquilliser.]]
*[[it:Ferrocene|Ferrocene]]
*[[it:Scopolamine|Scopolamine, the (Former) Truth Drug]]
*[[it:Camptothecin|Camptothecin,Anti-cancer agent ]]
*[[it:Salmeterol|Salmeterol, an agonist used to treat asthma]]
*[[it:Psilocin|Psilocin]]
*[[it:Epibatidine|Epibatidine]]
*[[it:Beta Carotene|Beta Carotene]]
*[[it:Thyroxine|Thyroxine, the Thyroid Hormone]]
*[[it:Tetrahydrocannabinol|Tetrahydrocannabinol]]
*[[it:Linalool|Linalool(A component of essential oil)]]
*[[it:Dihydroartemisinin| Dihydroartemisinin, An Active Anti-Malarial]]
*[[it:Acrolein|Acrolein]]
*[[it:Cinnamaldehyde|Cinnamaldehyde: The smell and taste in the spice cinnamon]]
*[[it:Melatonin|Melatonin: The All-Natural Nightcap]]
*[[it:Benzylpiperazine|Benzylpiperazine (BZP): Party Pills]]
*[[it:Vanillin|Vanillin, flavouring used in food]]
*[[it:Gingerol|Gingerol, precursor of Zingerone]]
*[[it:MSG|MSG; because everyone loves the flavour]]
*[[it:DDT|DDT, Pesticide]]
*[[it:Oseltamivir|Oseltamivir, neuraminidase inhibitor]]
*[[it:Caffeine|Caffeine]]
*[[it:Fullerene]]
*[[it:Histrionicotoxin]]
*[[it:limonene]]
*[[it:Capsanthin]]
*[[it:Safrole|Safrole: A formerly popular food and drinks additive]]
*[[it:Adenosine_Triphosphate|Adenosine Triphosphate (ATP), Energy source in muscles]]
*[[it:Aspartame|Aspartame: Artificial sweetener]]
*[[it:Astemizole|Astemizole:non-sedating anti-histamine]]
*[[it:Flucloxacillin|Flucloxacillin:antibiotic]]
*[[it:Quinine|Quinine: The Perfect Tonic for Any Fever]]
*[[it:Caramel|Caramel]]
*[[it:Azithromycin|Azithromycin]]
*[[it:Artemisinin|Artemisinin: An antimalarial drug]]
*[[it:Bradykinin|Bradykinin]]
*[[it:Carminic_acid|Carminic acid, Red colouring agent]]
*[[it:Oxytocin|Oxytocin: The Hormone of Love]]
*[[it:Carmoisine|Carmoisine]]
*[[it:Ziegler-Natta|Ziegler-Natta]]
*[[it:Cyclamate|Cyclamate]]
*[[it:Polyurethane|Polyurethane]]
*[[it:sexithiophene|sexithiophene]]
*[[it:Polydimethylsiloxane|Polydimethylsiloxane: Silicon-based organic polymer]]
*[[it:Lycopene|Lycopene: the red antioxidant molecule]]
*[[it:Mustard Gas|Mustard Gas]]
*[[it:Saxitoxin|Shellfish Poison]]
*[[it:Luminol|Luminol: Chemiluminescence Reactions]]
*[[it:Tumor Necrosis Factor|Tumour Necrosis Factor]]
*[[it:Tamiflu|Tamiflu: Antiviral]]
*[[it:Warfarin|Warfarin: Blood thinner]]
*[[it:Vitamin C|Ascorbic acid: Vitamin C]]
*[[it:Hexahelicene|Hexahelicene]]
*[[it:Cocaine|Cocaine]]
*[[it:Eucalyptol|Eucalyptol: The main component of eucalyptus oil]]
*[[it:dichlorodifluromethane| Dichlorodifluromethane]]

== Overlaps ==

If someone else starts editing a page at the same time as you, the system will detect this and offer alternatives for you to deal with. For example, it may suggest you copy the contents of the page you have been editing and merge it into the other person's page,
so that both the sets of edits are preserved. Read the on-screen instructions carefully!

Another precaution you could take is to keep a copy of the contents of the page you are editing in eg Wordpad (or Word),
make the changes there, and then copy the entire lot to the Wiki page to preview and then save. That way, if your contribution
is overlapped by someone else, you will still have a copy, and you can then resubmit it.
----
--[[User:Rzepa|Rzepa]] 12:25, 19 October 2006 (BST)--[[User:Rzepa|Rzepa]] 08:31, 5 November 2006 (UTC)

== Wiki Utillities ==
Utilities have been written to help the conversion of material from HTML.

# [http://diberri.dyndns.org/wikipedia/html2wiki/ A HTML2Wiki Converter]

No wiki2html converter suitable for use has yet been identified.
=== Wiki Templates ===

[[Template:DOI]] and [[Template:Doi-inline]] are providea as (protected) templates for your use. Many other templates exist, often to be found on e.g. Wikipedia pages. You may decide one of these is of particular use, or of interest. If so, you can install it on the wiki here for you and others to use. Add below a line that looks like {{template-name|parameter}}, save, and click on the red text to create the new template. If you prefer the task of adding useful templates to that of adding information about molecules, then you will be given full credit for performing this valuable service for others!
--[[User:Rzepa|Rzepa]] 14:41, 20 October 2006 (BST)

----
[[Template:Chem-Data]]

[[Template:Drug-Box]] - For pharmaceutical drugs just copy variable names and code generates tables

[[Template:Chembox supplement]] - to be linked to from the supplementary section of the table in the template above, for usage see [[Template_talk:chembox_supplement|here]]

[[Template:NFPA_704]] - for notes on how to use, see [[Template_talk:NFPA_704|here]]

[[R & S Phrases]]

It:projects

2006-12-06T11:10:34Z

Dh405: /* Export Pages */

__FORCETOC__

'''''You MUST use the Edit buttons on the right to edit this content. Do NOT use the Edit button on the top of this page.'''''
== Sandbox (Play-Pen) ==

This is an area where you can play without worrying what you do. Enter it by pressing the [Edit] button '''on the right''' and '''not''' at the top. Go here for a [http://en.wikipedia.org/wiki/Wikipedia:Cheatsheet ''cheat sheet''] summary of how to create a Wiki page. It's a free-for-all in here! Learn how to use a Wiki by coming here! PS This is how to do Greek: Α, α, β Δ, δ
Try copying/pasting some of the [http://www.ch.ic.ac.uk/local/it/lab1.html examples in the course work] into this page. See the effect by selecting '''Show Preview'''. No not use '''Save Page''' so as to leave this area uncluttered for others.
----
{|
|NEW: This demonstrates the use of Jmol loading discrete molecule files (rather than having to paste them into the wiki page). Upload the molecule file, and invoke it as shown here. Use it for eg loading large proteins etc. Sorry about the delay in getting this working, but the cause was pretty unobvious.--[[User:Rzepa|Rzepa]] 16:07, 4 December 2006 (UTC)
<center><jmol>
<jmolApplet>
<title>Pentahelicene</title><color>yellow</color>
<uploadedFileContents>Pentahelicene.mol</uploadedFileContents>
</jmolApplet>
<jmolMenu>
<item><text>Start spinning</text><script>spin on</script></item>
<item><text>Stop spinning</text><script>spin off</script></item>
<menuHeight>-1</menuHeight>
</jmolMenu>
<jmolButton>
<script>console</script>
<text>open a console window</text>
</jmolButton>
</jmol></center>
-----
<center><jmol><jmolAppletButton><title>Show Pentahelicene in popup window</title><color>cyan</color>
<uploadedFileContents>Pentahelicene.mol</uploadedFileContents></jmolAppletButton>
</jmol></center>

== Main Project Page ==
'''Please do not edit this page itself'''. Click on one of the titles to start editing.
{| summary="CIT Project Titles" border="1"
! bgcolor="cyan" |Project Number
! bgcolor="cyan" |General Keywords
|-
| bgcolor="#CCFF00" |01
| bgcolor="#CCFF00" | [[it:Lignocaine|Lignocaine (used in dentistry as a "local")]]
|-
| bgcolor="#CCFF00" |02
| bgcolor="#66FF99" | [[it:Piperine|Piperine (active ingredient of both black and white pepper)]]
|-
| bgcolor="#CCFF00" |03
| bgcolor="#CCFF00" | [[it:Rapamycin|Rapamycin (prevents transplant rejection)]]
|-
| bgcolor="#CCFF00" |04
| bgcolor="#66FF99" | [[it:Gossypol|Gossypol (male birth control)]]
|-
| bgcolor="#CCFF00" |05
| bgcolor="#CCFF00" | [[it:Gentamycin|Gentamicin A (aminoglycoside antibiotic)]]
|-
| bgcolor="#CCFF00" |06
| bgcolor="#66FF99" | [[it:Herceptin|Herceptin (topical anticancer drug)]]
|-
| bgcolor="#CCFF00" |07
| bgcolor="#CCFF00" | [[it:Gingerone|Zingerone (the characteristic smell of ginger)]]
|-
| bgcolor="#CCFF00" |08
| bgcolor="#66FF99" | [[it:Sucralose|Sucralose (non-metabolizable sweetening agent)]]
|-
| bgcolor="#CCFF00" |09
| bgcolor="#CCFF00" | [[it:Bufotoxin|Bufotoxin (active component of the toad ''Bufo vulgaris'')]]
|-
| bgcolor="#CCFF00" |10
| bgcolor="#66FF99" | [[it:Roaccutane|Roaccutane (treatment for severe acne)]]
|-
| bgcolor="#CCFF00" |11
| bgcolor="#CCFF00" | [[it:Sibutramine|Sibutramine (appetite suppresor)]]
|-
| bgcolor="#CCFF00" |12
| bgcolor="#66FF99" | [[it:Anandamide|Anandamide (the "feel-good" factor in chocolate)]]
|-
| bgcolor="#CCFF00" |13
| bgcolor="#CCFF00" | [[it:h3nbh3|Ammonia-borane: H3N-BH3 (Hydrogen storage molecule?)]]
|-
| bgcolor="#CCFF00" |14
| bgcolor="#66FF99" | [[it:Methoxsalen|Methoxsalen (Treatment of psoriasis)]]
|-
| bgcolor="#CCFF00" |15
| bgcolor="#CCFF00" | [[it:Hycocine|Hyoscine (From Mandrake and Witches Henbane, pre-med before surgery)]]
|-
| bgcolor="#CCFF00" |16
| bgcolor="#66FF99" | [[it:Capreomycin|Capreomycin (Drug-resistant TB)]]
|-
| bgcolor="#CCFF00" |17
| bgcolor="#CCFF00" | [[it:wilkinson|Wilkinson's catalyst]]
|-
| bgcolor="#CCFF00" |18
| bgcolor="#66FF99" | [[it:Jacobsen|Jacobsen's epoxidation catalyst]]
|-
| bgcolor="#CCFF00" |19
| bgcolor="#CCFF00" | [[it:Methylaluminoxane|Methylaluminoxane: MAO - hugely important ethylene polymerisation cocatalyst]]
|-
| bgcolor="#CCFF00" |20
| bgcolor="#66FF99" | [[it:Schwartz|Schwartz reagent for the hydrozirconation of alkenes and alkynes]]
|-
| bgcolor="#CCFF00" |21
| bgcolor="#CCFF00" | [[it:Schrock|Schrock metathesis catalyst]]
|-
| bgcolor="#CCFF00" |22
| bgcolor="#66FF99" | [[it:knots|Molecular-scale knots (nanoscale devices)]]
|-
|bgcolor="#CCFF00" |23
| bgcolor="#CCFF00" | [[it:Vioxx|Vioxx (treatment of osteoarthritis symptoms and pain)]]
|-
| bgcolor="#CCFF00" |24
| bgcolor="#66FF99" | [[it:Sertraline|Sertraline HCl (anti-depression)]]
|-
| bgcolor="#CCFF00" |25
| bgcolor="#CCFF00" | [[it:Ceftriaxone|Ceftriaxone (Gonorrhoea)]]
|-
| bgcolor="#CCFF00" |26
| bgcolor="#66FF99" | [[it:Zithromycin|Zithromycin (anti-infective)]]
|-
| bgcolor="#CCFF00" |27
| bgcolor="#CCFF00" | [[it:Lipitor|Lipitor (Cholesterol reducing agent)]]
|-
| bgcolor="#CCFF00" |28
| bgcolor="#66FF99" | [[it:Cyameluric Acid|Cyameluric acid (Linus Pauling's last idea!)]]
|}

== Supplemental Project Page ==

This area is for people who wish to create their own projects if none of the above appeal to them. Click on the '''Edit''' button to the right to open up an editable page,
then add an entry below as follows

*<nowiki> [[it:name_of_project|Descriptive name of intended project]]</nowiki>
*This will produce the effect: [[it:name_of_project|Descriptive name of intended project]]
----
*[[it:sitagliptin_page|Sitagliptin]]
*[[it:Retinal|Retinal, molecule of sight]]
*[[it:Tamoxifen|Tamoxifen, breast cancer treatment]]
*[[it:Morphine|Morphine, painkiller]]
*[[it:Pelargonidin|Pelargonidin, colouring in nature]]
*[[it:Propanil|Propanil, weedkiller]]
*[[it:Ranitidine|Ranitidine, antiulcerative]]
*[[it:chlorphentermine|chlorphentermine, anorectic]]
*[[it:Serotonin|Serotonin, The 'HAPPY' Drug]]
*[[it:Amphidinolide T1|Amphidinolide T1]]
*[[it:Rosiglitazone|Rosiglitazone, drug that is currently used to treat diabetes.]]
*[[it:Furosemide|Furosemide]]
*[[it:Tryptophan|Tryptophan]]
*[[it:methylpentynol|methylpentynol, tranquilliser.]]
*[[it:Ferrocene|Ferrocene]]
*[[it:Scopolamine|Scopolamine, the (Former) Truth Drug]]
*[[it:Camptothecin|Camptothecin,Anti-cancer agent ]]
*[[it:Salmeterol|Salmeterol, an agonist used to treat asthma]]
*[[it:Psilocin|Psilocin]]
*[[it:Epibatidine|Epibatidine]]
*[[it:Beta Carotene|Beta Carotene]]
*[[it:Thyroxine|Thyroxine, the Thyroid Hormone]]
*[[it:Tetrahydrocannabinol|Tetrahydrocannabinol]]
*[[it:Linalool|Linalool(A component of essential oil)]]
*[[it:Dihydroartemisinin| Dihydroartemisinin, An Active Anti-Malarial]]
*[[it:Acrolein|Acrolein]]
*[[it:Cinnamaldehyde|Cinnamaldehyde: The smell and taste in the spice cinnamon]]
*[[it:Melatonin|Melatonin: The All-Natural Nightcap]]
*[[it:Benzylpiperazine|Benzylpiperazine (BZP): Party Pills]]
*[[it:Vanillin|Vanillin, flavouring used in food]]
*[[it:Gingerol|Gingerol, precursor of Zingerone]]
*[[it:MSG|MSG; because everyone loves the flavour]]
*[[it:DDT|DDT, Pesticide]]
*[[it:Oseltamivir|Oseltamivir, neuraminidase inhibitor]]
*[[it:Caffeine|Caffeine]]
*[[it:Fullerene]]
*[[it:Histrionicotoxin]]
*[[it:limonene]]
*[[it:Capsanthin]]
*[[it:Safrole|Safrole: A formerly popular food and drinks additive]]
*[[it:Adenosine_Triphosphate|Adenosine Triphosphate (ATP), Energy source in muscles]]
*[[it:Aspartame|Aspartame: Artificial sweetener]]
*[[it:Astemizole|Astemizole:non-sedating anti-histamine]]
*[[it:Flucloxacillin|Flucloxacillin:antibiotic]]
*[[it:Quinine|Quinine: The Perfect Tonic for Any Fever]]
*[[it:Caramel|Caramel]]
*[[it:Azithromycin|Azithromycin]]
*[[it:Artemisinin|Artemisinin: An antimalarial drug]]
*[[it:Bradykinin|Bradykinin]]
*[[it:Carminic_acid|Carminic acid, Red colouring agent]]
*[[it:Oxytocin|Oxytocin: The Hormone of Love]]
*[[it:Carmoisine|Carmoisine]]
*[[it:Ziegler-Natta|Ziegler-Natta]]
*[[it:Cyclamate|Cyclamate]]
*[[it:Polyurethane|Polyurethane]]
*[[it:sexithiophene|sexithiophene]]
*[[it:Polydimethylsiloxane|Polydimethylsiloxane: Silicon-based organic polymer]]
*[[it:Lycopene|Lycopene: the red antioxidant molecule]]
*[[it:Mustard Gas|Mustard Gas]]
*[[it:Saxitoxin|Shellfish Poison]]
*[[it:Luminol|Luminol: Chemiluminescence Reactions]]
*[[it:Tumor Necrosis Factor|Tumour Necrosis Factor]]
*[[it:Tamiflu|Tamiflu: Antiviral]]
*[[it:Warfarin|Warfarin: Blood thinner]]
*[[it:Vitamin C|Ascorbic acid: Vitamin C]]

it:dichlorodifluromethane

== Overlaps ==

If someone else starts editing a page at the same time as you, the system will detect this and offer alternatives for you to deal with. For example, it may suggest you copy the contents of the page you have been editing and merge it into the other person's page,
so that both the sets of edits are preserved. Read the on-screen instructions carefully!

Another precaution you could take is to keep a copy of the contents of the page you are editing in eg Wordpad (or Word),
make the changes there, and then copy the entire lot to the Wiki page to preview and then save. That way, if your contribution
is overlapped by someone else, you will still have a copy, and you can then resubmit it.
----
--[[User:Rzepa|Rzepa]] 12:25, 19 October 2006 (BST)--[[User:Rzepa|Rzepa]] 08:31, 5 November 2006 (UTC)

== Wiki Utillities ==
Utilities have been written to help the conversion of material from HTML.

# [http://diberri.dyndns.org/wikipedia/html2wiki/ A HTML2Wiki Converter]

No wiki2html converter suitable for use has yet been identified.
=== Wiki Templates ===

[[Template:DOI]] and [[Template:Doi-inline]] are providea as (protected) templates for your use. Many other templates exist, often to be found on e.g. Wikipedia pages. You may decide one of these is of particular use, or of interest. If so, you can install it on the wiki here for you and others to use. Add below a line that looks like {{template-name|parameter}}, save, and click on the red text to create the new template. If you prefer the task of adding useful templates to that of adding information about molecules, then you will be given full credit for performing this valuable service for others!
--[[User:Rzepa|Rzepa]] 14:41, 20 October 2006 (BST)

----
[[Template:Chem-Data]]

[[Template:Drug-Box]] - For pharmaceutical drugs just copy variable names and code generates tables

[[Template:Chembox supplement]] - to be linked to from the supplementary section of the table in the template above, for usage see [[Template_talk:chembox_supplement|here]]

[[Template:NFPA_704]] - for notes on how to use, see [[Template_talk:NFPA_704|here]]

[[R & S Phrases]]