File:Ceh15 borazine charge.PNG

2018-05-17T15:10:26Z

Ceh15:

File:Ceh15 benzene charge.PNG

2018-05-17T15:10:16Z

Ceh15:

ICC:ceh15

2018-05-17T15:01:32Z

2018-05-17T13:41:45Z

Ceh15:

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

[[File:Ceh15_bh3_freq.png|Summary of calculation.]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000049 0.000450 YES
RMS Force 0.000025 0.000300 YES
Maximum Displacement 0.000193 0.001800 YES
RMS Displacement 0.000097 0.001200 YES
</pre>

[[Media:CEH15_BH3_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -0.2279 -0.0080 0.0004 22.0037 22.0049 24.0346
Low frequencies --- 1163.1731 1213.2725 1213.2727
</pre>

<jmol><jmolApplet>
<title>Borane</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_BH3_FREQ,LOG.txt</uploadedFileContents>
</jmolApplet></jmol>

====Vibrational spectrum for BH3====
{| class="wikitable"
|+
|-
|wavenumber (cm-1) || Intensity (arbitrary units) || symmetry || IR active? || type
|-
|1163
|92
|A2"
|yes
|out-of-plane bend
|-
|1213
|14
|E'
|very slight
|bend
|-
|1213
|14
|E'
|very slight
|bend
|-
|2582
|0
|A1'
|no
|symmetric stretch
|-
|2715
|126
|E'
|yes
|asymmetric stretch
|-
|2715
|126
|E'
|yes
|asymmetric stretch
|}

[[File:Ceh15_bh3_spectrum.PNG|thumb|Calculated BH3 IR spectrum.]]

In the spectrum of BH3, three peaks can be seen, however, 6 vibrations are listen in the table calculated by Gaussian. This is because some of the peaks have the same frequency, i.e. are degenerate. However this only accounts for two of the missing peaks. The third peak is missing because it is no IR active, since the dipole moment doesn't change during the vibration. This means that the intensity of this peak is 0 in the table, and it doesn't show up on the spectrum.

====Molectular Orbitals of BH3====

[[File:Ceh15_bh3_MO_PH.PNG|thumb|MO diagram of BH3 by Patricia Hunt,<ref name="PHunt_MO" /> modified to include computationally calculated MOs. The 1s orbital of boron has not been included, since it is not sufficiently high in energy to be involved in bonding.]]

There are not significant differences between the calculated and LCAO molecular orbitals. For this molecule, qualitative molecular orbital theory is sufficient to describe the orbitals and bonding. However, for larger and more complex molecules, it may not be sufficiently accurate.

==NH3: B3LYP/6-31G level==

[[File:Ceh15_nh3_freq.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000006 0.000450 YES
RMS Force 0.000003 0.000300 YES
Maximum Displacement 0.000013 0.001800 YES
RMS Displacement 0.000007 0.001200 YES
</pre>

[[Media:CEH15_NH3_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -0.0137 -0.0026 0.0012 7.0783 8.0932 8.0937
Low frequencies --- 1089.3840 1693.9368 1693.9368
</pre>

<jmol><jmolApplet>
<title>Ammonia</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_NH3_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

====Vibrational spectrum for NH3====
{| class="wikitable"
|+
|-
|wavenumber (cm-1) || Intensity (arbitrary units) || symmetry || IR active? || type
|-
|1089
|145
|A
|yes
|out-of-plane bend
|-
|1694
|14
|E
|very slight
|bend
|-
|1694
|14
|E
|very slight
|bend
|-
|3461
|1
|A
|very slight
|symmetric stretch
|-
|3590
|0
|E
|no
|asymmetric stretch
|-
|3590
|0
|E
|no
|asymmetric stretch
|}

[[File:Ceh15_nh3_spectrum.PNG|thumb|Calculated NH3]]

==NH3BH3: B3LYP/6-31G level==

[[File:Ceh15_nh3bh3_freq.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000116 0.000450 YES
RMS Force 0.000060 0.000300 YES
Maximum Displacement 0.000579 0.001800 YES
RMS Displacement 0.000346 0.001200 YES
</pre>

[[Media:CEH15_NH3BH3_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -0.0017 -0.0014 -0.0010 16.2531 17.3981 37.2581
Low frequencies --- 265.8400 632.1980 639.2687
</pre>

<jmol><jmolApplet>
<title>Ammonia-Borane Complex</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_NH3BH3_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

====Vibrational spectrum for NH3BH3====
{| class="wikitable"
|+
|-
|wavenumber (cm-1) || Intensity (arbitrary units) || symmetry || IR active? || type
|-
|266
|0
|A
|no
|torsion
|-
|632
|14
|A
|very slight
|symmetric stretch
|-
|639
|4
|A
|very slight
|bend
|-
|639
|4
|A
|very slight
|bend
|-
|1069
|40
|A
|yes
|bend
|-
|1069
|40
|A
|yes
|bend
|-
|1196
|109
|A
|yes
|borane out of plane bend
|-
|1203
|3
|A
|very slight
|borane bend
|-
|1203
|3
|A
|very slight
|borane bend
|-
|1329
|114
|A
|yes
|ammonia out of plane bend
|-
|1676
|28
|A
|yes
|ammonia bend
|-
|1676
|28
|A
|yes
|ammonia bend
|-
|2470
|67
|A
|yes
|borane symmetric stretch
|-
|2530
|231
|A
|yes
|borane asymmetric stretch
|-
|2530
|231
|A
|yes
|borane asymmetric strech
|-
|3463
|2
|A
|very slight
|ammonia symmetric stretch
|-
|3579
|28
|A
|yes
|ammonia asymmetric stretch
|-
|3579
|28
|A
|yes
|ammonia asymmetric stretch
|}

[[File:Ceh15_nh3bh3_spectrum.PNG|thumb|Calculated NH3BH3]]

====Ammonia-Borane Association Energies====

{| class="wikitable"
|+
|-
|Molecule || Energy /a.u.
|-
|NH3
| -56.55777
|-
|BH3
| -26.61532
|-
|NH3BH3
| -83.22469
|}

ΔE = E(NH3BH3)-[E(NH3)+E(BH3)] = -0.05160 a.u. = -129 kJ.mol-1

The B-N dative bond is reasonably weak, when compared with the C-C single bond, which has an energy of 346 kJ.mol-1.<ref name="carbon" />

==BBr3: B3LYP/6-31G(d,p) LanL2DZ level==

{{DOI|10042/202416}}

[[File:Ceh15_bbr3_freq.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000008 0.000450 YES
RMS Force 0.000004 0.000300 YES
Maximum Displacement 0.000037 0.001800 YES
RMS Displacement 0.000018 0.001200 YES
</pre>

[[Media:CEH15_BBR3_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -2.3055 -0.0029 -0.0018 0.0774 0.7534 0.7534
Low frequencies --- 155.9402 155.9405 267.6894
</pre>

<jmol><jmolApplet>
<title>BBr3</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_BBR3_FREQ.LOG.log</uploadedFileContents>
</jmolApplet></jmol>

==Aromaticity Project==

===Benzene Key Information: B3LYP/6-31G level===

[[File:Ceh15_benzene_freq.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000187 0.000450 YES
RMS Force 0.000091 0.000300 YES
Maximum Displacement 0.000823 0.001800 YES
RMS Displacement 0.000358 0.001200 YES
</pre>

[[Media:CEH15_BENZENE_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -13.7810 -12.9763 -11.9029 -0.0003 0.0003 0.0005
Low frequencies --- 414.0699 414.1914 620.9703
</pre>

<jmol><jmolApplet>
<title>Benzene</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_BENZENE_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

===Borazine Key Information: B3LYP/6-31G level===

[[File:Ceh15_borazine_freq.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000202 0.000450 YES
RMS Force 0.000064 0.000300 YES
Maximum Displacement 0.000300 0.001800 YES
RMS Displacement 0.000106 0.001200 YES
</pre>

[[Media:CEH15_BORAZINE_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -5.9262 -0.0010 -0.0005 0.0005 5.1016 8.3042
Low frequencies --- 289.5657 289.6523 404.3296
</pre>

<jmol><jmolApplet>
<title>Borazine</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_BORAZINE_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

===

==References==
<references>
<ref name="PHunt_MO">P. Hunt, Molecular Orbitals Lecture Course, Pippard Lecture Theatre, Imperial College London, November, 2017.</ref>
<ref name="carbon">Wired Chemist, http://www.wiredchemist.com/chemistry/data/bond_energies_lengths.html, accessed 16th May 2018</ref>
</references>

ICC:ceh15

2018-05-17T13:39:41Z

Ceh15: /* Aromaticity Project */

==BH3==

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

[[File:Ceh15_bh3_freq.png|Summary of calculation.]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000049 0.000450 YES
RMS Force 0.000025 0.000300 YES
Maximum Displacement 0.000193 0.001800 YES
RMS Displacement 0.000097 0.001200 YES
</pre>

[[Media:CEH15_BH3_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -0.2279 -0.0080 0.0004 22.0037 22.0049 24.0346
Low frequencies --- 1163.1731 1213.2725 1213.2727
</pre>

<jmol><jmolApplet>
<title>Borane</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_BH3_FREQ,LOG.txt</uploadedFileContents>
</jmolApplet></jmol>

====Vibrational spectrum for BH3====
{| class="wikitable"
|+
|-
|wavenumber (cm-1) || Intensity (arbitrary units) || symmetry || IR active? || type
|-
|1163
|92
|A2"
|yes
|out-of-plane bend
|-
|1213
|14
|E'
|very slight
|bend
|-
|1213
|14
|E'
|very slight
|bend
|-
|2582
|0
|A1'
|no
|symmetric stretch
|-
|2715
|126
|E'
|yes
|asymmetric stretch
|-
|2715
|126
|E'
|yes
|asymmetric stretch
|}

[[File:Ceh15_bh3_spectrum.PNG|thumb|Calculated BH3 IR spectrum.]]

In the spectrum of BH3, three peaks can be seen, however, 6 vibrations are listen in the table calculated by Gaussian. This is because some of the peaks have the same frequency, i.e. are degenerate. However this only accounts for two of the missing peaks. The third peak is missing because it is no IR active, since the dipole moment doesn't change during the vibration. This means that the intensity of this peak is 0 in the table, and it doesn't show up on the spectrum.

====Molectular Orbitals of BH3====

[[File:Ceh15_bh3_MO_PH.PNG|thumb|MO diagram of BH3 by Patricia Hunt,<ref name="PHunt_MO" /> modified to include computationally calculated MOs. The 1s orbital of boron has not been included, since it is not sufficiently high in energy to be involved in bonding.]]

There are not significant differences between the calculated and LCAO molecular orbitals. For this molecule, qualitative molecular orbital theory is sufficient to describe the orbitals and bonding. However, for larger and more complex molecules, it may not be sufficiently accurate.

==NH3==

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

[[File:Ceh15_nh3_freq.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000006 0.000450 YES
RMS Force 0.000003 0.000300 YES
Maximum Displacement 0.000013 0.001800 YES
RMS Displacement 0.000007 0.001200 YES
</pre>

[[Media:CEH15_NH3_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -0.0137 -0.0026 0.0012 7.0783 8.0932 8.0937
Low frequencies --- 1089.3840 1693.9368 1693.9368
</pre>

<jmol><jmolApplet>
<title>Ammonia</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_NH3_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

====Vibrational spectrum for NH3====
{| class="wikitable"
|+
|-
|wavenumber (cm-1) || Intensity (arbitrary units) || symmetry || IR active? || type
|-
|1089
|145
|A
|yes
|out-of-plane bend
|-
|1694
|14
|E
|very slight
|bend
|-
|1694
|14
|E
|very slight
|bend
|-
|3461
|1
|A
|very slight
|symmetric stretch
|-
|3590
|0
|E
|no
|asymmetric stretch
|-
|3590
|0
|E
|no
|asymmetric stretch
|}

[[File:Ceh15_nh3_spectrum.PNG|thumb|Calculated NH3]]

==NH3BH3==

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

[[File:Ceh15_nh3bh3_freq.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000116 0.000450 YES
RMS Force 0.000060 0.000300 YES
Maximum Displacement 0.000579 0.001800 YES
RMS Displacement 0.000346 0.001200 YES
</pre>

[[Media:CEH15_NH3BH3_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -0.0017 -0.0014 -0.0010 16.2531 17.3981 37.2581
Low frequencies --- 265.8400 632.1980 639.2687
</pre>

<jmol><jmolApplet>
<title>Ammonia-Borane Complex</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_NH3BH3_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

====Vibrational spectrum for NH3BH3====
{| class="wikitable"
|+
|-
|wavenumber (cm-1) || Intensity (arbitrary units) || symmetry || IR active? || type
|-
|266
|0
|A
|no
|torsion
|-
|632
|14
|A
|very slight
|symmetric stretch
|-
|639
|4
|A
|very slight
|bend
|-
|639
|4
|A
|very slight
|bend
|-
|1069
|40
|A
|yes
|bend
|-
|1069
|40
|A
|yes
|bend
|-
|1196
|109
|A
|yes
|borane out of plane bend
|-
|1203
|3
|A
|very slight
|borane bend
|-
|1203
|3
|A
|very slight
|borane bend
|-
|1329
|114
|A
|yes
|ammonia out of plane bend
|-
|1676
|28
|A
|yes
|ammonia bend
|-
|1676
|28
|A
|yes
|ammonia bend
|-
|2470
|67
|A
|yes
|borane symmetric stretch
|-
|2530
|231
|A
|yes
|borane asymmetric stretch
|-
|2530
|231
|A
|yes
|borane asymmetric strech
|-
|3463
|2
|A
|very slight
|ammonia symmetric stretch
|-
|3579
|28
|A
|yes
|ammonia asymmetric stretch
|-
|3579
|28
|A
|yes
|ammonia asymmetric stretch
|}

[[File:Ceh15_nh3bh3_spectrum.PNG|thumb|Calculated NH3BH3]]

====Ammonia-Borane Association Energies====

{| class="wikitable"
|+
|-
|Molecule || Energy /a.u.
|-
|NH3
| -56.55777
|-
|BH3
| -26.61532
|-
|NH3BH3
| -83.22469
|}

ΔE = E(NH3BH3)-[E(NH3)+E(BH3)] = -0.05160 a.u. = -129 kJ.mol-1

The B-N dative bond is reasonably weak, when compared with the C-C single bond, which has an energy of 346 kJ.mol-1.<ref name="carbon" />

==BBr3==

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

{{DOI|10042/202416}}

[[File:Ceh15_bbr3_freq.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000008 0.000450 YES
RMS Force 0.000004 0.000300 YES
Maximum Displacement 0.000037 0.001800 YES
RMS Displacement 0.000018 0.001200 YES
</pre>

[[Media:CEH15_BBR3_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -2.3055 -0.0029 -0.0018 0.0774 0.7534 0.7534
Low frequencies --- 155.9402 155.9405 267.6894
</pre>

<jmol><jmolApplet>
<title>BBr3</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_BBR3_FREQ.LOG.log</uploadedFileContents>
</jmolApplet></jmol>

==Aromaticity Project==

===Benzene Key Information===

[[File:Ceh15_benzene_freq.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000187 0.000450 YES
RMS Force 0.000091 0.000300 YES
Maximum Displacement 0.000823 0.001800 YES
RMS Displacement 0.000358 0.001200 YES
</pre>

[[Media:CEH15_BENZENE_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -13.7810 -12.9763 -11.9029 -0.0003 0.0003 0.0005
Low frequencies --- 414.0699 414.1914 620.9703
</pre>

<jmol><jmolApplet>
<title>Benzene</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_BENZENE_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

===Borazine Key Information===

[[File:Ceh15_borazine_freq.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000202 0.000450 YES
RMS Force 0.000064 0.000300 YES
Maximum Displacement 0.000300 0.001800 YES
RMS Displacement 0.000106 0.001200 YES
</pre>

[[Media:CEH15_BORAZINE_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -5.9262 -0.0010 -0.0005 0.0005 5.1016 8.3042
Low frequencies --- 289.5657 289.6523 404.3296
</pre>

<jmol><jmolApplet>
<title>Borazine</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_BORAZINE_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

===

==References==
<references>
<ref name="PHunt_MO">P. Hunt, Molecular Orbitals Lecture Course, Pippard Lecture Theatre, Imperial College London, November, 2017.</ref>
<ref name="carbon">Wired Chemist, http://www.wiredchemist.com/chemistry/data/bond_energies_lengths.html, accessed 16th May 2018</ref>
</references>

ICC:ceh15

2018-05-17T12:50:13Z

Ceh15: /* Aromaticity Project */

==BH3==

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

[[File:Ceh15_bh3_freq.png|Summary of calculation.]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000049 0.000450 YES
RMS Force 0.000025 0.000300 YES
Maximum Displacement 0.000193 0.001800 YES
RMS Displacement 0.000097 0.001200 YES
</pre>

[[Media:CEH15_BH3_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -0.2279 -0.0080 0.0004 22.0037 22.0049 24.0346
Low frequencies --- 1163.1731 1213.2725 1213.2727
</pre>

<jmol><jmolApplet>
<title>Borane</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_BH3_FREQ,LOG.txt</uploadedFileContents>
</jmolApplet></jmol>

====Vibrational spectrum for BH3====
{| class="wikitable"
|+
|-
|wavenumber (cm-1) || Intensity (arbitrary units) || symmetry || IR active? || type
|-
|1163
|92
|A2"
|yes
|out-of-plane bend
|-
|1213
|14
|E'
|very slight
|bend
|-
|1213
|14
|E'
|very slight
|bend
|-
|2582
|0
|A1'
|no
|symmetric stretch
|-
|2715
|126
|E'
|yes
|asymmetric stretch
|-
|2715
|126
|E'
|yes
|asymmetric stretch
|}

[[File:Ceh15_bh3_spectrum.PNG|thumb|Calculated BH3 IR spectrum.]]

In the spectrum of BH3, three peaks can be seen, however, 6 vibrations are listen in the table calculated by Gaussian. This is because some of the peaks have the same frequency, i.e. are degenerate. However this only accounts for two of the missing peaks. The third peak is missing because it is no IR active, since the dipole moment doesn't change during the vibration. This means that the intensity of this peak is 0 in the table, and it doesn't show up on the spectrum.

====Molectular Orbitals of BH3====

[[File:Ceh15_bh3_MO_PH.PNG|thumb|MO diagram of BH3 by Patricia Hunt,<ref name="PHunt_MO" /> modified to include computationally calculated MOs. The 1s orbital of boron has not been included, since it is not sufficiently high in energy to be involved in bonding.]]

There are not significant differences between the calculated and LCAO molecular orbitals. For this molecule, qualitative molecular orbital theory is sufficient to describe the orbitals and bonding. However, for larger and more complex molecules, it may not be sufficiently accurate.

==NH3==

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

[[File:Ceh15_nh3_freq.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000006 0.000450 YES
RMS Force 0.000003 0.000300 YES
Maximum Displacement 0.000013 0.001800 YES
RMS Displacement 0.000007 0.001200 YES
</pre>

[[Media:CEH15_NH3_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -0.0137 -0.0026 0.0012 7.0783 8.0932 8.0937
Low frequencies --- 1089.3840 1693.9368 1693.9368
</pre>

<jmol><jmolApplet>
<title>Ammonia</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_NH3_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

====Vibrational spectrum for NH3====
{| class="wikitable"
|+
|-
|wavenumber (cm-1) || Intensity (arbitrary units) || symmetry || IR active? || type
|-
|1089
|145
|A
|yes
|out-of-plane bend
|-
|1694
|14
|E
|very slight
|bend
|-
|1694
|14
|E
|very slight
|bend
|-
|3461
|1
|A
|very slight
|symmetric stretch
|-
|3590
|0
|E
|no
|asymmetric stretch
|-
|3590
|0
|E
|no
|asymmetric stretch
|}

[[File:Ceh15_nh3_spectrum.PNG|thumb|Calculated NH3]]

==NH3BH3==

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

[[File:Ceh15_nh3bh3_freq.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000116 0.000450 YES
RMS Force 0.000060 0.000300 YES
Maximum Displacement 0.000579 0.001800 YES
RMS Displacement 0.000346 0.001200 YES
</pre>

[[Media:CEH15_NH3BH3_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -0.0017 -0.0014 -0.0010 16.2531 17.3981 37.2581
Low frequencies --- 265.8400 632.1980 639.2687
</pre>

<jmol><jmolApplet>
<title>Ammonia-Borane Complex</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_NH3BH3_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

====Vibrational spectrum for NH3BH3====
{| class="wikitable"
|+
|-
|wavenumber (cm-1) || Intensity (arbitrary units) || symmetry || IR active? || type
|-
|266
|0
|A
|no
|torsion
|-
|632
|14
|A
|very slight
|symmetric stretch
|-
|639
|4
|A
|very slight
|bend
|-
|639
|4
|A
|very slight
|bend
|-
|1069
|40
|A
|yes
|bend
|-
|1069
|40
|A
|yes
|bend
|-
|1196
|109
|A
|yes
|borane out of plane bend
|-
|1203
|3
|A
|very slight
|borane bend
|-
|1203
|3
|A
|very slight
|borane bend
|-
|1329
|114
|A
|yes
|ammonia out of plane bend
|-
|1676
|28
|A
|yes
|ammonia bend
|-
|1676
|28
|A
|yes
|ammonia bend
|-
|2470
|67
|A
|yes
|borane symmetric stretch
|-
|2530
|231
|A
|yes
|borane asymmetric stretch
|-
|2530
|231
|A
|yes
|borane asymmetric strech
|-
|3463
|2
|A
|very slight
|ammonia symmetric stretch
|-
|3579
|28
|A
|yes
|ammonia asymmetric stretch
|-
|3579
|28
|A
|yes
|ammonia asymmetric stretch
|}

[[File:Ceh15_nh3bh3_spectrum.PNG|thumb|Calculated NH3BH3]]

====Ammonia-Borane Association Energies====

{| class="wikitable"
|+
|-
|Molecule || Energy /a.u.
|-
|NH3
| -56.55777
|-
|BH3
| -26.61532
|-
|NH3BH3
| -83.22469
|}

ΔE = E(NH3BH3)-[E(NH3)+E(BH3)] = -0.05160 a.u. = -129 kJ.mol-1

The B-N dative bond is reasonably weak, when compared with the C-C single bond, which has an energy of 346 kJ.mol-1.<ref name="carbon" />

==BBr3==

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

{{DOI|10042/202416}}

[[File:Ceh15_bbr3_freq.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000008 0.000450 YES
RMS Force 0.000004 0.000300 YES
Maximum Displacement 0.000037 0.001800 YES
RMS Displacement 0.000018 0.001200 YES
</pre>

[[Media:CEH15_BBR3_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -2.3055 -0.0029 -0.0018 0.0774 0.7534 0.7534
Low frequencies --- 155.9402 155.9405 267.6894
</pre>

<jmol><jmolApplet>
<title>BBr3</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_BBR3_FREQ.LOG.log</uploadedFileContents>
</jmolApplet></jmol>

==Aromaticity Project==

===Benzene Key Information===

[[File:Ceh15_benzene_freq.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000187 0.000450 YES
RMS Force 0.000091 0.000300 YES
Maximum Displacement 0.000823 0.001800 YES
RMS Displacement 0.000358 0.001200 YES
</pre>

[[Media:CEH15_BENZENE_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -13.7810 -12.9763 -11.9029 -0.0003 0.0003 0.0005
Low frequencies --- 414.0699 414.1914 620.9703
</pre>

<jmol><jmolApplet>
<title>Benzene</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_BENZENE_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

===Borazine Key Information===

[[File:Ceh15_borazine_freq.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000202 0.000450 YES
RMS Force 0.000064 0.000300 YES
Maximum Displacement 0.000300 0.001800 YES
RMS Displacement 0.000106 0.001200 YES
</pre>

[[Media:CEH15_BORAZINE_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -5.9262 -0.0010 -0.0005 0.0005 5.1016 8.3042
Low frequencies --- 289.5657 289.6523 404.3296
</pre>

<jmol><jmolApplet>
<title>Borazine</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_BORAZINE_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

==References==
<references>
<ref name="PHunt_MO">P. Hunt, Molecular Orbitals Lecture Course, Pippard Lecture Theatre, Imperial College London, November, 2017.</ref>
<ref name="carbon">Wired Chemist, http://www.wiredchemist.com/chemistry/data/bond_energies_lengths.html, accessed 16th May 2018</ref>
</references>

ICC:ceh15

2018-05-17T12:47:15Z

Ceh15: /* Aromaticity Project */

==BH3==

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

[[File:Ceh15_bh3_freq.png|Summary of calculation.]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000049 0.000450 YES
RMS Force 0.000025 0.000300 YES
Maximum Displacement 0.000193 0.001800 YES
RMS Displacement 0.000097 0.001200 YES
</pre>

[[Media:CEH15_BH3_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -0.2279 -0.0080 0.0004 22.0037 22.0049 24.0346
Low frequencies --- 1163.1731 1213.2725 1213.2727
</pre>

<jmol><jmolApplet>
<title>Borane</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_BH3_FREQ,LOG.txt</uploadedFileContents>
</jmolApplet></jmol>

====Vibrational spectrum for BH3====
{| class="wikitable"
|+
|-
|wavenumber (cm-1) || Intensity (arbitrary units) || symmetry || IR active? || type
|-
|1163
|92
|A2"
|yes
|out-of-plane bend
|-
|1213
|14
|E'
|very slight
|bend
|-
|1213
|14
|E'
|very slight
|bend
|-
|2582
|0
|A1'
|no
|symmetric stretch
|-
|2715
|126
|E'
|yes
|asymmetric stretch
|-
|2715
|126
|E'
|yes
|asymmetric stretch
|}

[[File:Ceh15_bh3_spectrum.PNG|thumb|Calculated BH3 IR spectrum.]]

In the spectrum of BH3, three peaks can be seen, however, 6 vibrations are listen in the table calculated by Gaussian. This is because some of the peaks have the same frequency, i.e. are degenerate. However this only accounts for two of the missing peaks. The third peak is missing because it is no IR active, since the dipole moment doesn't change during the vibration. This means that the intensity of this peak is 0 in the table, and it doesn't show up on the spectrum.

====Molectular Orbitals of BH3====

[[File:Ceh15_bh3_MO_PH.PNG|thumb|MO diagram of BH3 by Patricia Hunt,<ref name="PHunt_MO" /> modified to include computationally calculated MOs. The 1s orbital of boron has not been included, since it is not sufficiently high in energy to be involved in bonding.]]

There are not significant differences between the calculated and LCAO molecular orbitals. For this molecule, qualitative molecular orbital theory is sufficient to describe the orbitals and bonding. However, for larger and more complex molecules, it may not be sufficiently accurate.

==NH3==

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

[[File:Ceh15_nh3_freq.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000006 0.000450 YES
RMS Force 0.000003 0.000300 YES
Maximum Displacement 0.000013 0.001800 YES
RMS Displacement 0.000007 0.001200 YES
</pre>

[[Media:CEH15_NH3_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -0.0137 -0.0026 0.0012 7.0783 8.0932 8.0937
Low frequencies --- 1089.3840 1693.9368 1693.9368
</pre>

<jmol><jmolApplet>
<title>Ammonia</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_NH3_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

====Vibrational spectrum for NH3====
{| class="wikitable"
|+
|-
|wavenumber (cm-1) || Intensity (arbitrary units) || symmetry || IR active? || type
|-
|1089
|145
|A
|yes
|out-of-plane bend
|-
|1694
|14
|E
|very slight
|bend
|-
|1694
|14
|E
|very slight
|bend
|-
|3461
|1
|A
|very slight
|symmetric stretch
|-
|3590
|0
|E
|no
|asymmetric stretch
|-
|3590
|0
|E
|no
|asymmetric stretch
|}

[[File:Ceh15_nh3_spectrum.PNG|thumb|Calculated NH3]]

==NH3BH3==

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

[[File:Ceh15_nh3bh3_freq.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000116 0.000450 YES
RMS Force 0.000060 0.000300 YES
Maximum Displacement 0.000579 0.001800 YES
RMS Displacement 0.000346 0.001200 YES
</pre>

[[Media:CEH15_NH3BH3_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -0.0017 -0.0014 -0.0010 16.2531 17.3981 37.2581
Low frequencies --- 265.8400 632.1980 639.2687
</pre>

<jmol><jmolApplet>
<title>Ammonia-Borane Complex</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_NH3BH3_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

====Vibrational spectrum for NH3BH3====
{| class="wikitable"
|+
|-
|wavenumber (cm-1) || Intensity (arbitrary units) || symmetry || IR active? || type
|-
|266
|0
|A
|no
|torsion
|-
|632
|14
|A
|very slight
|symmetric stretch
|-
|639
|4
|A
|very slight
|bend
|-
|639
|4
|A
|very slight
|bend
|-
|1069
|40
|A
|yes
|bend
|-
|1069
|40
|A
|yes
|bend
|-
|1196
|109
|A
|yes
|borane out of plane bend
|-
|1203
|3
|A
|very slight
|borane bend
|-
|1203
|3
|A
|very slight
|borane bend
|-
|1329
|114
|A
|yes
|ammonia out of plane bend
|-
|1676
|28
|A
|yes
|ammonia bend
|-
|1676
|28
|A
|yes
|ammonia bend
|-
|2470
|67
|A
|yes
|borane symmetric stretch
|-
|2530
|231
|A
|yes
|borane asymmetric stretch
|-
|2530
|231
|A
|yes
|borane asymmetric strech
|-
|3463
|2
|A
|very slight
|ammonia symmetric stretch
|-
|3579
|28
|A
|yes
|ammonia asymmetric stretch
|-
|3579
|28
|A
|yes
|ammonia asymmetric stretch
|}

[[File:Ceh15_nh3bh3_spectrum.PNG|thumb|Calculated NH3BH3]]

====Ammonia-Borane Association Energies====

{| class="wikitable"
|+
|-
|Molecule || Energy /a.u.
|-
|NH3
| -56.55777
|-
|BH3
| -26.61532
|-
|NH3BH3
| -83.22469
|}

ΔE = E(NH3BH3)-[E(NH3)+E(BH3)] = -0.05160 a.u. = -129 kJ.mol-1

The B-N dative bond is reasonably weak, when compared with the C-C single bond, which has an energy of 346 kJ.mol-1.<ref name="carbon" />

==BBr3==

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

{{DOI|10042/202416}}

[[File:Ceh15_bbr3_freq.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000008 0.000450 YES
RMS Force 0.000004 0.000300 YES
Maximum Displacement 0.000037 0.001800 YES
RMS Displacement 0.000018 0.001200 YES
</pre>

[[Media:CEH15_BBR3_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -2.3055 -0.0029 -0.0018 0.0774 0.7534 0.7534
Low frequencies --- 155.9402 155.9405 267.6894
</pre>

<jmol><jmolApplet>
<title>BBr3</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_BBR3_FREQ.LOG.log</uploadedFileContents>
</jmolApplet></jmol>

==Aromaticity Project==

===Benzene Key Information===

[[File:Ceh15_benzene_freq.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000187 0.000450 YES
RMS Force 0.000091 0.000300 YES
Maximum Displacement 0.000823 0.001800 YES
RMS Displacement 0.000358 0.001200 YES
</pre>

[[Media:CEH15_BENZENE_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -13.7810 -12.9763 -11.9029 -0.0003 0.0003 0.0005
Low frequencies --- 414.0699 414.1914 620.9703
</pre>

<jmol><jmolApplet>
<title>Benzene</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_BENZENE_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

===Borazine Key Information===

[[File:Ceh15_borazine_freq.PNG]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000006 0.000450 YES
RMS Force 0.000003 0.000300 YES
Maximum Displacement 0.000013 0.001800 YES
RMS Displacement 0.000007 0.001200 YES
</pre>

[[Media:CEH15_BORAZINE_FREQ.LOG| Frequency analysis log file]]

<pre>
Low frequencies --- -0.0137 -0.0026 0.0012 7.0783 8.0932 8.0937
Low frequencies --- 1089.3840 1693.9368 1693.9368
</pre>

<jmol><jmolApplet>
<title>Ammonia</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>CEH15_BORAZINE_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

==References==
<references>
<ref name="PHunt_MO">P. Hunt, Molecular Orbitals Lecture Course, Pippard Lecture Theatre, Imperial College London, November, 2017.</ref>
<ref name="carbon">Wired Chemist, http://www.wiredchemist.com/chemistry/data/bond_energies_lengths.html, accessed 16th May 2018</ref>
</references>