File:Hg3117 mo68.png

2019-05-24T16:03:34Z

Hg3117:

File:Hg3117 mo72.png

2019-05-24T15:47:00Z

Hg3117:

Hg3117 inorganic

2019-05-24T15:46:35Z

Hg3117:

'''BH3'''

'''B3LYP/6-31G'''

[[File:Hg3117 bh3 inorganic summary.png|none|thumb]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000203 0.000450 YES
RMS Force 0.000098 0.000300 YES
Maximum Displacement 0.000737 0.001800 YES
RMS Displacement 0.000395 0.001200 YES
Predicted change in Energy=-1.354985D-07

Low frequencies --- -0.2263 -0.1037 -0.0055 47.9770 49.0378 49.0383
Low frequencies --- 1163.7209 1213.6704 1213.6731
</pre>

[[Media:HARRYGEMMILL_BH3_FREQ.LOG|BH3 Log File Link]]

<jmol><jmolApplet>
<title>BH3</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>HARRYGEMMILL_BH3_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

'''Vibrational Modes for BH3'''

[[File:hg3117_bh3_vibration_table.png]]

'''IR Spectrum of BH3'''

[[File:hg3117_bh3_spectrum.png]]

There are less than 6 peaks observable in the spectrum even though there are 6 possible vibrational modes in BH3 for several reasons.
First if the vibrational mode doesn't cause an overall change in the molecules dipole it is labelled as IR inactive and won't show up on the IR spectrum. In this case the vibrational mode with wavenumber 2580cm^-1 is Inactive as it is a symmetric stretch. All H atoms stretch away from the B atom in equal amounts so no overall change in dipole.
The second reason is that some of the modes are degenerate. These will show up as one peak on the spectrum. This applies to the peaks at 1214cm^-1 and 2713cm^-1. So due to both IR inactivity and degeneracy the predicted number of observable peaks in the spectrum would be 3 which is reflected in the spectrum shown above.

[[File:hg3117_BH3_MO_Finished.png]]
'''BH3 MO Diagram with LCAO's and Corresponding Computed MOs''' /ref. 1

The LCAO's and real MOs share the same nodes. The main differences in the MOs is that the ones by LCAO are much less diffused. This shows that qualitative MO theory is a good approximation of a molecule's MOs when they can't be computed more accurately.

'''NH3]]'''

'''B3LYP/6-31G'''

[[File:hg3117_nh3_summary.png]]

<pre>

Item Value Threshold Converged?
Maximum Force 0.000006 0.000450 YES
RMS Force 0.000004 0.000300 YES
Maximum Displacement 0.000014 0.001800 YES
RMS Displacement 0.000009 0.001200 YES
Predicted change in Energy=-1.141618D-10

Low frequencies --- -426.8524 -426.8509 -385.8927 -0.0077 -0.0013 0.0080
Low frequencies --- 790.4011 1653.0881 1653.0884

</pre>

[[Media:HARRYGEMMILL_NH3_FREQ.LOG|NH3 Log File Link]]

<jmol><jmolApplet>
<title>NH3</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>HARRYGEMMILL_NH3_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

'''Vibrational Modes for NH3'''

[[File:hg3117_nh3_vibration_modes.png]]

'''NH3 IR Spectrum'''

[[File:hg3117_nh3_spectrum.png]]

'''NH3BH3'''

'''B3LYP/6-31G'''

[[File:hg3117_nh3bh3_summary.png]]

<pre>

Item Value Threshold Converged?
Maximum Force 0.000122 0.000450 YES
RMS Force 0.000058 0.000300 YES
Maximum Displacement 0.000513 0.001800 YES
RMS Displacement 0.000296 0.001200 YES
Predicted change in Energy=-1.631175D-07

Low frequencies --- -798.6159 -403.1874 -402.1497 -0.0007 0.0006 0.0009
Low frequencies --- 641.0195 641.6344 912.1445

</pre>

[[Media:HARRYGEMMILL_NH3BH3_FREQ_OPT.LOG|NH3 Log File Link]]

<jmol><jmolApplet>
<title>NH3BH3</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>HARRYGEMMILL_NH3BH3_FREQ_OPT.LOG</uploadedFileContents>
</jmolApplet></jmol>

[[File:hg3117_nh3bh3_vibration_table.png]]

[[File:hg3117_nh3bh3_spectrum.png]]

'''Energy Change'''

'''au and KJ/Mol'''

Change in E = E(NH3BH3) - (E(NH3) + E(BH3))

= -83.22468893 - (-26.61532343 + -56.55776873)
= -0.05159 au
= -135.52 KJ/mol

'''NI3'''

'''B3LYP/6-31G'''

[[File:hg3117_ni3_summary.png]]

<pre>

Item Value Threshold Converged?
Maximum Force 0.000061 0.000450 YES
RMS Force 0.000037 0.000300 YES
Maximum Displacement 0.000459 0.001800 YES
RMS Displacement 0.000285 0.001200 YES
Predicted change in Energy=-3.108653D-08
</pre>

[[Media:hg3117_thurs_ni3_scan_2.log|NI3 Log File Link]]

<jmol><jmolApplet>
<title>NI3</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>hg3117_thurs_ni3_scan_2.log</uploadedFileContents>
</jmolApplet></jmol>

The optimised N-I bond distance is 2.10503 angstroms.

'''Project Molecule - Al2Br2Cl4'''

'''B3LYP/6-31G'''

'''Five Isomers of Al2Cl4Br2'''

'''Relative Energies of Isomers with 2 Bridging Br Atoms and 2 Cis Bromines'''

<jmol><jmolApplet>
<title>Al2Cl4Br2 - Bridging Bromine</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>HG3117_2BR_BRIDGING_OPT.LOG</uploadedFileContents>
</jmolApplet></jmol>

[[File:hg3117_Br_Bridging_Summary.png]]

<jmol><jmolApplet>
<title>Al2Cl4Br2 - Trans Bromine</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>HG3117_CL_TRANS_OPT.LOG</uploadedFileContents>
</jmolApplet></jmol>

[[File:hg3117_Br_Trans_summary.png]]

Trans Br energy = -7469.53762au = -19618240.27 KJ/mol

2 Bridging Br = -7469.54269au = -19618253.59 KJ/mol

relative energy Bridging:Trans is 1:0.99999, difference in energy of 13.32KJ/mol

More stable isomer is the one with 2 bridging Br ligands. This is due to Br being a better Lewis Base than Cl as its outer electron pairs aren't held as strongly.

'''Dissociation Energy - lowest energy isomer'''

The energy of the AlCl2Br dissociation product is -3734.74852au
Energy change is 2E(AlCl2Br) - E(Al2Cl4Br2) = 2(-3734.74852) - (-7469.54269) = 0.04565au = 119.90KJ/mol.

The energy of the products is higher than that of the dimer, so are less stable.

'''Al2Cl4Br2 Computed MO Comparison with LCAO's'''

'''MO 77 - Overall Antibonding'''

[[File:hg3117_mo77.png]]

'''MO 72 - Overall Antibonding'''

[[File:hg3117_mo72.png]]

'''References'''

ref. 1 - P. Hunt, Available at https://www.huntresearchgroup.org.uk/teaching/teaching_comp_lab_year2a/Tut_MO_diagram_BH3.pdf

2019-05-23T13:57:02Z

Hg3117:

Hg3117 inorganic

2019-05-23T13:56:40Z

Hg3117:

'''BH3'''

'''B3LYP/6-31G'''

[[File:Hg3117 bh3 inorganic summary.png|none|thumb]]

<pre>
Item Value Threshold Converged?
Maximum Force 0.000203 0.000450 YES
RMS Force 0.000098 0.000300 YES
Maximum Displacement 0.000737 0.001800 YES
RMS Displacement 0.000395 0.001200 YES
Predicted change in Energy=-1.354985D-07

Low frequencies --- -0.2263 -0.1037 -0.0055 47.9770 49.0378 49.0383
Low frequencies --- 1163.7209 1213.6704 1213.6731
</pre>

[[Media:HARRYGEMMILL_BH3_FREQ.LOG|BH3 Log File Link]]

<jmol><jmolApplet>
<title>BH3</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>HARRYGEMMILL_BH3_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

'''Vibrational Modes for BH3'''

[[File:hg3117_bh3_vibration_table.png]]

'''IR Spectrum of BH3'''

[[File:hg3117_bh3_spectrum.png]]

There are less than 6 peaks observable in the spectrum even though there are 6 possible vibrational modes in BH3 for several reasons.
First if the vibrational mode doesn't cause an overall change in the molecules dipole it is labelled as IR inactive and won't show up on the IR spectrum. In this case the vibrational mode with wavenumber 2580cm^-1 is Inactive as it is a symmetric stretch. All H atoms stretch away from the B atom in equal amounts so no overall change in dipole.
The second reason is that some of the modes are degenerate. These will show up as one peak on the spectrum. This applies to the peaks at 1214cm^-1 and 2713cm^-1. So due to both IR inactivity and degeneracy the predicted number of observable peaks in the spectrum would be 3 which is reflected in the spectrum shown above.

[[File:hg3117_BH3_MO_Finished.png]]
'''BH3 MO Diagram with LCAO's and Corresponding Computed MOs''' /ref. 1

The LCAO's and real MOs share the same nodes. The main differences in the MOs is that the ones by LCAO are much less diffused. This shows that qualitative MO theory is a good approximation of a molecule's MOs when they can't be computed more accurately.

'''NH3]]'''

'''B3LYP/6-31G'''

[[File:hg3117_nh3_summary.png]]

<pre>

Item Value Threshold Converged?
Maximum Force 0.000006 0.000450 YES
RMS Force 0.000004 0.000300 YES
Maximum Displacement 0.000014 0.001800 YES
RMS Displacement 0.000009 0.001200 YES
Predicted change in Energy=-1.141618D-10

Low frequencies --- -426.8524 -426.8509 -385.8927 -0.0077 -0.0013 0.0080
Low frequencies --- 790.4011 1653.0881 1653.0884

</pre>

[[Media:HARRYGEMMILL_NH3_FREQ.LOG|NH3 Log File Link]]

<jmol><jmolApplet>
<title>NH3</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>HARRYGEMMILL_NH3_FREQ.LOG</uploadedFileContents>
</jmolApplet></jmol>

'''Vibrational Modes for NH3'''

[[File:hg3117_nh3_vibration_modes.png]]

'''NH3 IR Spectrum'''

[[File:hg3117_nh3_spectrum.png]]

'''NH3BH3'''

'''B3LYP/6-31G'''

[[File:hg3117_nh3bh3_summary.png]]

<pre>

Item Value Threshold Converged?
Maximum Force 0.000122 0.000450 YES
RMS Force 0.000058 0.000300 YES
Maximum Displacement 0.000513 0.001800 YES
RMS Displacement 0.000296 0.001200 YES
Predicted change in Energy=-1.631175D-07

Low frequencies --- -798.6159 -403.1874 -402.1497 -0.0007 0.0006 0.0009
Low frequencies --- 641.0195 641.6344 912.1445

</pre>

[[Media:HARRYGEMMILL_NH3BH3_FREQ_OPT.LOG|NH3 Log File Link]]

<jmol><jmolApplet>
<title>NH3BH3</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>HARRYGEMMILL_NH3BH3_FREQ_OPT.LOG</uploadedFileContents>
</jmolApplet></jmol>

[[File:hg3117_nh3bh3_vibration_table.png]]

[[File:hg3117_nh3bh3_spectrum.png]]

'''Energy Change'''

'''au and KJ/Mol'''

Change in E = E(NH3BH3) - (E(NH3) + E(BH3))

= -83.22468893 - (-26.61532343 + -56.55776873)
= -0.05159 au
= -135.52 KJ/mol

'''NI3'''

'''B3LYP/6-31G'''

[[File:hg3117_ni3_summary.png]]

'''Project Molecule - Al2Br2Cl4'''

'''B3LYP/6-31G'''

'''Five Isomers of Al2Cl4Br2'''

'''Relative Energies of Isomers with 2 Bridging Br Atoms and 2 Cis Bromines'''

<jmol><jmolApplet>
<title>Al2Cl4Br2 - Bridging Bromine</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>HG3117_2BR_BRIDGING_OPT.LOG</uploadedFileContents>
</jmolApplet></jmol>

[[File:hg3117_Br_Bridging_Summary.png]]

<jmol><jmolApplet>
<title>Al2Cl4Br2 - Trans Bromine</title>
<color>black</color>
<size>200</size>
<uploadedFileContents>HG3117_CL_TRANS_OPT.LOG</uploadedFileContents>
</jmolApplet></jmol>

[[File:hg3117_Br_Trans_summary.png]]

Trans Br energy = -7469.53762au = -19618240.27 KJ/mol

2 Bridging Br = -7469.54269au = -19618253.59 KJ/mol

relative energy Bridging:Trans is 1:0.99999, difference in energy of 13.32KJ/mol

More stable isomer is the one with 2 bridging Br ligands. This is due to Br being a better Lewis Base than Cl as its outer electron pairs aren't held as strongly.

'''Dissociation Energy - lowest energy isomer'''

The energy of the AlCl2Br dissociation product is -3734.74852au
Energy change is 2E(AlCl2Br) - E(Al2Cl4Br2) = 2(-3734.74852) - (-7469.54269) = 0.04565au = 119.90KJ/mol.

'''References'''

ref. 1 - P. Hunt, Available at https://www.huntresearchgroup.org.uk/teaching/teaching_comp_lab_year2a/Tut_MO_diagram_BH3.pdf

2019-05-22T13:12:16Z

Hg3117: