ChemWiki - User contributions [en]

Nk1016InorgCCL

2018-05-18T16:02:03Z

Nk1016: /* Lewis acids and bases */

= Year 2 Inorganic Computational Chemistry Lab =

== BH3 ==
'''B3LYP/6-31G level'''

[[File:NK1016_BH3_optsumm.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000012 0.000450 YES
RMS Force 0.000008 0.000300 YES
Maximum Displacement 0.000064 0.001800 YES
RMS Displacement 0.000039 0.001200 YES
</pre>

Frequency analysis log file [[Media:NK1016_BH3_FREQ.LOG]]

<pre>
Low frequencies --- -10.0599 -3.0201 -0.0054 0.4917 2.0912 3.6735
Low frequencies --- 1162.9537 1213.1540 1213.1567
</pre>

<jmol><jmolApplet>
<title> BH3 </title>
<size>200</size>
<uploadedFileContents>NK1016_BH3_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

{| class="wikitable" border="1"
|+ Vibrations
! Vibration !! Intensity !! Symmetry !! IR Active? !! Type
|-
| 1163 || 93 || A2'' || Yes || Bend
|-
| 1213 || 14 || E' || Yes || Bend
|-
| 1213 || 14 || E' || Yes || Bend
|-
| 2582 || 0 || A' || No || Stretch
|-
| 2716 || 126 || E' || Yes || Stretch
|-
| 2716 || 126 || E' || Yes || Stretch
|}

[[File:NK1016_BH3_IR.PNG|500px]]

There are less than 6 peaks as one vibration is not IR active, and there are 2 pairs of degenerate vibrations so only 3 peaks are visible.

MO Diagram:

[[File:nk1016_BH3_MO_diagram_all.jpg]]

The real and LCAO MOs are very similar in what they represent.

i.e. They both show the same nodes and give similar electron densities.

This shows that qualitative MO theory is very useful when it comes to predicting "real" MOs.

Ammonia-Borane:

E(NH3) = -56.55777 a.u.

E(BH3) = -26.61532 a.u.

E(NH3BH3) = -83.22469 a.u.

ΔE=E(NH3BH3)-[E(NH3)+E(BH3)]

ΔE = -0.05160 a.u. (-140 KJ/mol)

This is a sensible value for the bond energy as you expect it to be around a couple hundred kilo-joules per mole.

I would say that the B-N dative bond is relatively weak as an N-N single bond has an energy of ~167 KJ/mol while an N-N triple bond (one of the strongest bond around) has an energy of ~942 KJ/mol.

== BBr3 ==
'''B3LYP/6-31G(d,p)LANL2DZ level'''

[[File:NK1016_BBr3_optsumm.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000013 0.000450 YES
RMS Force 0.000006 0.000300 YES
Maximum Displacement 0.000051 0.001800 YES
RMS Displacement 0.000035 0.001200 YES
</pre>

Frequency analysis log file {{DOI|10042/202419}}

<pre>
Low frequencies --- -0.0002 -0.0002 -0.0001 49.7266 49.8710 50.0368
Low frequencies --- 144.7443 144.7665 215.6321
</pre>

<jmol><jmolApplet>
<title> BBr3 </title>
<size>200</size>
<uploadedFileContents>NK1016_BBR3_FREQ_fin.log</uploadedFileContents>
</jmolApplet></jmol>

== Lewis acids and bases ==

There are 5 possible isomers of Al2Cl4Br2 and these are shown below:

[[File:All_Isomers_wpg.PNG]]

With the isomer with 2 bridging Br ions as isomer (a) and the isomer with 2 bridging Cl ions and trans terminal Br as isomer (b), here are the optimized data for isomer (a) and (b).

'''B3LYP/6-31G(d,p)LANL2DZ level'''

Isomer (a):

[[File:NK1016_Lew_Ac_BBr_optsumm.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000068 0.000450 YES
RMS Force 0.000028 0.000300 YES
Maximum Displacement 0.001359 0.001800 YES
RMS Displacement 0.000586 0.001200 YES
</pre>

Isomer (b):

[[File:NK1016_Lew_Ac_BCl_optsumm.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000072 0.000450 YES
RMS Force 0.000028 0.000300 YES
Maximum Displacement 0.001169 0.001800 YES
RMS Displacement 0.000404 0.001200 YES
</pre>

Using the energies calculated, isomer b can be found to be 0.00999 a.u. (26 KJ/mol) more stable than isomer a.

This shows that a smaller bridging ion like Cl gives a more stable compound than a larger bridging ion like Br.

Dissociation Energy: 0.03606 a.u. (90 KJ/mol)

Further analysis was performed on isomer b (the lowest energy isomer) and its MOs were visualised:

[[File:NK1016Lew_Ac_BCl_MOBdia.PNG]]

[[File:NK1016Lew_Ac_BCl_MOMBdia.PNG]]

[[File:NK1016Lew_Ac_BCl_MOABdia.PNG]]

Nk1016InorgCCL

2018-05-18T16:00:38Z

Nk1016:

= Year 2 Inorganic Computational Chemistry Lab =

== BH3 ==
'''B3LYP/6-31G level'''

[[File:NK1016_BH3_optsumm.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000012 0.000450 YES
RMS Force 0.000008 0.000300 YES
Maximum Displacement 0.000064 0.001800 YES
RMS Displacement 0.000039 0.001200 YES
</pre>

Frequency analysis log file [[Media:NK1016_BH3_FREQ.LOG]]

<pre>
Low frequencies --- -10.0599 -3.0201 -0.0054 0.4917 2.0912 3.6735
Low frequencies --- 1162.9537 1213.1540 1213.1567
</pre>

<jmol><jmolApplet>
<title> BH3 </title>
<size>200</size>
<uploadedFileContents>NK1016_BH3_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

{| class="wikitable" border="1"
|+ Vibrations
! Vibration !! Intensity !! Symmetry !! IR Active? !! Type
|-
| 1163 || 93 || A2'' || Yes || Bend
|-
| 1213 || 14 || E' || Yes || Bend
|-
| 1213 || 14 || E' || Yes || Bend
|-
| 2582 || 0 || A' || No || Stretch
|-
| 2716 || 126 || E' || Yes || Stretch
|-
| 2716 || 126 || E' || Yes || Stretch
|}

[[File:NK1016_BH3_IR.PNG|500px]]

There are less than 6 peaks as one vibration is not IR active, and there are 2 pairs of degenerate vibrations so only 3 peaks are visible.

MO Diagram:

[[File:nk1016_BH3_MO_diagram_all.jpg]]

The real and LCAO MOs are very similar in what they represent.

i.e. They both show the same nodes and give similar electron densities.

This shows that qualitative MO theory is very useful when it comes to predicting "real" MOs.

Ammonia-Borane:

E(NH3) = -56.55777 a.u.

E(BH3) = -26.61532 a.u.

E(NH3BH3) = -83.22469 a.u.

ΔE=E(NH3BH3)-[E(NH3)+E(BH3)]

ΔE = -0.05160 a.u. (-140 KJ/mol)

This is a sensible value for the bond energy as you expect it to be around a couple hundred kilo-joules per mole.

I would say that the B-N dative bond is relatively weak as an N-N single bond has an energy of ~167 KJ/mol while an N-N triple bond (one of the strongest bond around) has an energy of ~942 KJ/mol.

== BBr3 ==
'''B3LYP/6-31G(d,p)LANL2DZ level'''

[[File:NK1016_BBr3_optsumm.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000013 0.000450 YES
RMS Force 0.000006 0.000300 YES
Maximum Displacement 0.000051 0.001800 YES
RMS Displacement 0.000035 0.001200 YES
</pre>

Frequency analysis log file {{DOI|10042/202419}}

<pre>
Low frequencies --- -0.0002 -0.0002 -0.0001 49.7266 49.8710 50.0368
Low frequencies --- 144.7443 144.7665 215.6321
</pre>

<jmol><jmolApplet>
<title> BBr3 </title>
<size>200</size>
<uploadedFileContents>NK1016_BBR3_FREQ_fin.log</uploadedFileContents>
</jmolApplet></jmol>

== Lewis acids and bases ==

There are 5 possible isomers of Al2Cl4Br2 and these are shown below:

[[File:All_Isomers_wpg.PNG]]

With the isomer with 2 bridging Br ions as isomer (a) and the isomer with 2 bridging Cl ions and trans terminal Br as isomer (b), here are the optimized data for isomer (a) and (b).

'''B3LYP/6-31G(d,p)LANL2DZ level'''

Isomer (a):

[[File:NK1016_Lew_Ac_BBr_optsumm.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000068 0.000450 YES
RMS Force 0.000028 0.000300 YES
Maximum Displacement 0.001359 0.001800 YES
RMS Displacement 0.000586 0.001200 YES
</pre>

Isomer (b):

[[File:NK1016_Lew_Ac_BCl_optsumm.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000072 0.000450 YES
RMS Force 0.000028 0.000300 YES
Maximum Displacement 0.001169 0.001800 YES
RMS Displacement 0.000404 0.001200 YES
</pre>

Using the energies calculated, isomer b can be found to be 0.00999 a.u. (26 KJ/mol) more stable than isomer a.

This shows that a smaller bridging ion like Cl gives a more stable compound than a larger bridging ion like Br.

Dissociation Energy: 0.03606 a.u. (90 KJ/mol)

Further analysis was performed on isomer b (the lowest energy isomer) and its MOs were visualised:

[[File:NK1016_Lew_Ac_BCl_MOBdia.PNG]]

[[File:NK1016_Lew_Ac_BCl_MOMBdia.PNG]]

[[File:NK1016_Lew_Ac_BCl_MOABdia.PNG]]

File:NK1016Lew Ac BCl MOMBdia.PNG

2018-05-18T15:59:13Z

Nk1016:

File:NK1016Lew Ac BCl MOBdia.PNG

2018-05-18T15:58:46Z

Nk1016:

File:NK1016Lew Ac BCl MOABdia.PNG

2018-05-18T15:57:03Z

Nk1016:

Nk1016InorgCCL

2018-05-18T15:13:17Z

Nk1016: /* Lewis acids and bases */

Nk1016InorgCCL

2018-05-18T14:33:14Z

Nk1016:

= Year 2 Inorganic Computational Chemistry Lab =

== BH3 ==
'''B3LYP/6-31G level'''

[[File:NK1016_BH3_optsumm.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000012 0.000450 YES
RMS Force 0.000008 0.000300 YES
Maximum Displacement 0.000064 0.001800 YES
RMS Displacement 0.000039 0.001200 YES
</pre>

Frequency analysis log file [[Media:NK1016_BH3_FREQ.LOG]]

<pre>
Low frequencies --- -10.0599 -3.0201 -0.0054 0.4917 2.0912 3.6735
Low frequencies --- 1162.9537 1213.1540 1213.1567
</pre>

<jmol><jmolApplet>
<title> BH3 </title>
<size>200</size>
<uploadedFileContents>NK1016_BH3_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

{| class="wikitable" border="1"
|+ Vibrations
! Vibration !! Intensity !! Symmetry !! IR Active? !! Type
|-
| 1163 || 93 || A2'' || Yes || Bend
|-
| 1213 || 14 || E' || Yes || Bend
|-
| 1213 || 14 || E' || Yes || Bend
|-
| 2582 || 0 || A' || No || Stretch
|-
| 2716 || 126 || E' || Yes || Stretch
|-
| 2716 || 126 || E' || Yes || Stretch
|}

[[File:NK1016_BH3_IR.PNG|500px]]

There are less than 6 peaks as one vibration is not IR active, and there are 2 pairs of degenerate vibrations so only 3 peaks are visible.

MO Diagram:

[[File:nk1016_BH3_MO_diagram_all.jpg]]

The real and LCAO MOs are very similar in what they represent.

i.e. They both show the same nodes and give similar electron densities.

This shows that qualitative MO theory is very useful when it comes to predicting "real" MOs.

Ammonia-Borane:

E(NH3) = -56.55777 a.u.

E(BH3) = -26.61532 a.u.

E(NH3BH3) = -83.22469 a.u.

ΔE=E(NH3BH3)-[E(NH3)+E(BH3)]

ΔE = -0.05160 a.u. (-140 KJ/mol)

This is a sensible value for the bond energy as you expect it to be around a couple hundred kilo-joules per mole.

I would say that the B-N dative bond is relatively weak as an N-N single bond has an energy of ~167 KJ/mol while an N-N triple bond (one of the strongest bond around) has an energy of ~942 KJ/mol.

== BBr3 ==
'''B3LYP/6-31G(d,p)LANL2DZ level'''

[[File:NK1016_BBr3_optsumm.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000013 0.000450 YES
RMS Force 0.000006 0.000300 YES
Maximum Displacement 0.000051 0.001800 YES
RMS Displacement 0.000035 0.001200 YES
</pre>

Frequency analysis log file {{DOI|10042/202419}}

<pre>
Low frequencies --- -0.0002 -0.0002 -0.0001 49.7266 49.8710 50.0368
Low frequencies --- 144.7443 144.7665 215.6321
</pre>

<jmol><jmolApplet>
<title> BBr3 </title>
<size>200</size>
<uploadedFileContents>NK1016_BBR3_FREQ_fin.log</uploadedFileContents>
</jmolApplet></jmol>

== Lewis acids and bases ==

There are 5 possible isomers of Al2Cl4Br2 and these are shown below:

[[File:All_Isomers_wpg.PNG]]

With the isomer with 2 bridging Br ions as isomer (a) and the isomer with 2 bridging Cl ions and trans terminal Br as isomer (b), here are the optimized data for isomer (a) and (b).

'''B3LYP/6-31G(d,p)LANL2DZ level'''

Isomer (a):

[[File:NK1016_Lew_Ac_BBr_optsumm.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000068 0.000450 YES
RMS Force 0.000028 0.000300 YES
Maximum Displacement 0.001359 0.001800 YES
RMS Displacement 0.000586 0.001200 YES
</pre>

Isomer (b):

[[File:NK1016_Lew_Ac_BCl_optsumm.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000072 0.000450 YES
RMS Force 0.000028 0.000300 YES
Maximum Displacement 0.001169 0.001800 YES
RMS Displacement 0.000404 0.001200 YES
</pre>

Using the energies calculated, isomer b can be found to be 0.00999 a.u. (26 KJ/mol) more stable than isomer a.

This shows that a smaller bridging ion like Cl gives a more stable compound than a larger bridging ion like Br.

Dissociation Energy:

Further analysis was performed on isomer b (the lowest energy isomer) and its MOs were visualised

File:NK1016 Lew Ac BCl FREQ.log

2018-05-18T14:23:04Z

Nk1016:

Nk1016InorgCCL

2018-05-18T14:10:17Z

Nk1016:

Nk1016InorgCCL

2018-05-18T14:04:55Z

Nk1016:

File:NK1016 Lew Ac BCl optsumm.PNG

2018-05-18T14:03:34Z

Nk1016:

File:NK1016 Lew Ac BBr optsumm.PNG

2018-05-18T14:03:16Z

Nk1016:

Nk1016InorgCCL

2018-05-18T13:54:38Z

Nk1016: /* Lewis acids and bases */

Nk1016InorgCCL

2018-05-18T13:17:12Z

Nk1016: /* Lewis acids and bases */

Nk1016InorgCCL

2018-05-18T13:17:03Z

Nk1016: /* Lewis acids and bases */

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2018-05-18T13:16:39Z

Nk1016: /* Lewis acids and bases */

Nk1016InorgCCL

2018-05-18T13:14:50Z

Nk1016:

File:All Isomers wpg.PNG

2018-05-18T13:14:28Z

Nk1016:

File:NK1016 All Isomers.PNG

2018-05-18T13:13:56Z

Nk1016: Nk1016 uploaded a new version of File:NK1016 All Isomers.PNG

File:NK1016 All Isomers.PNG

2018-05-18T13:12:27Z

Nk1016: Nk1016 uploaded a new version of File:NK1016 All Isomers.PNG

Nk1016InorgCCL

2018-05-18T10:47:51Z

Nk1016:

Nk1016InorgCCL

2018-05-18T10:46:57Z

Nk1016: /* Lewis acids and bases */

File:NK1016 All Isomers.PNG

2018-05-17T14:04:41Z

Nk1016:

Nk1016InorgCCL

2018-05-17T13:40:13Z

Nk1016:

Nk1016InorgCCL

2018-05-17T13:28:08Z

Nk1016: /* BH3 */

Nk1016InorgCCL

2018-05-17T13:20:16Z

Nk1016: /* BH3 */

Nk1016InorgCCL

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Nk1016: /* BH3 */

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Nk1016InorgCCL

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Nk1016InorgCCL

2018-05-17T13:07:21Z

Nk1016:

File:NK1016 BBR3 FREQ fin.log

2018-05-17T13:05:43Z

Nk1016:

Nk1016InorgCCL

2018-05-17T13:02:53Z

Nk1016:

Nk1016InorgCCL

2018-05-17T11:47:26Z

Nk1016:

File:NK1016 BBr3 optsumm.PNG

2018-05-17T11:45:36Z

Nk1016:

Nk1016InorgCCL

2018-05-15T16:48:07Z

Nk1016:

Nk1016InorgCCL

2018-05-15T16:30:56Z

Nk1016:

Nk1016InorgCCL

2018-05-15T16:30:09Z

Nk1016: /* BH3 */

Nk1016InorgCCL

2018-05-15T16:06:39Z

Nk1016: /* BH3 */

Nk1016InorgCCL

2018-05-15T16:06:17Z

Nk1016: /* BH3 */

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Nk1016: /* BH3 */

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Nk1016: /* BH3 */

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Nk1016: /* BH3 */

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2018-05-15T16:04:53Z

Nk1016: /* BH3 */

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Nk1016: /* BH3 */

File:Nk1016 BH3 MO diagram all.jpg

2018-05-15T16:03:36Z

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Nk1016InorgCCL

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Nk1016: /* BH3 */

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2018-05-15T14:23:53Z

Nk1016: /* BH3 */

File:NK1016 BH3 IR.PNG

2018-05-15T14:21:20Z

Nk1016: