Rep:Mod:ag01500903

Molecular Modelling

NH₃

File:01500903ANNAGUO NH3OPT.LOG

OPT information

calculation method	basis set	final energy	RMS gradient	point group
RB3LYP	6-31G(d.p.)	-56.55776873a.u.	0.00000485a.u.	C3V

real output--item table

         Item               Value     Threshold  Converged?
 Maximum Force            0.000004     0.000450     YES
 RMS     Force            0.000004     0.000300     YES
 Maximum Displacement     0.000072     0.001800     YES
 RMS     Displacement     0.000035     0.001200     YES

vibration

wavenumber cm-1	1090	1694	1694	3461	3590	3590
symmetry	A1	E	E	A1	E	E
intensity arbitrary units	145	14	14	1	0	0
image

6 modes are expected from the 3N-6 rule.

The second and third modes are degenerated which have wavenumber of 1694cm^-1.

Also, the fifth and sixth modes are degenerated which have wavenumber of 3590cm^-1.

bending: 1090cm^-1, 1694cm^-1, 1694cm^-1

stretching: 3461cm^-1, 3590cm^-1, 3590cm^-1

3461cm^-1 one is highly symmetric.

1090cm^-1 one is umbrella mode.

2 bands are expected in experimental spectrum.

charge distribution

charge on N = -1.125

charge on H = +0.375

N is expected to be negatively charged and H is expected to be positively charged because N is more electronegative.

N₂

File:ANNAGUON2OPT.LOG

OPT information

calculation method	basis set	final energy	RMS gradient	point group
RB3LYP	6-31G(d.p.)	-109.52412868a.u.	0.00000134a.u.	D∞h

real output--item table

         Item               Value     Threshold  Converged?
 Maximum Force            0.000002     0.000450     YES
 RMS     Force            0.000002     0.000300     YES
 Maximum Displacement     0.000001     0.001800     YES
 RMS     Displacement     0.000001     0.001200     YES

vibration

wavenumber cm-1	2457
symmetry	SGG
intensity arbitrary units	0
image

charge distribution

H₂

File:01500903H2OPT.LOG

OPT information

calculation method	basis set	final energy	RMS gradient	point group
RB3LYP	6-31G(d.p.)	-1.17853936a.u.	0.00000023a.u.	D∞h

real output--item table

         Item               Value     Threshold  Converged?
 Maximum Force            0.000000     0.000450     YES
 RMS     Force            0.000000     0.000300     YES
 Maximum Displacement     0.000001     0.001800     YES
 RMS     Displacement     0.000001     0.001200     YES

vibration

wavenumber cm-1	4466
symmetry	SGG
intensity arbitrary units	0
image

charge distribution

Cl₂

File:ANNAGUOCL2OPT3.LOG

OPT information

calculation method	basis set	final energy	RMS gradient	point group
RB3LYP	6-31G(d.p.)	-920.3498788a.u.	0.00008611a.u.	D∞h

real output--item table

         Item               Value     Threshold  Converged?
 Maximum Force            0.000149     0.000450     YES
 RMS     Force            0.000149     0.000300     YES
 Maximum Displacement     0.000415     0.001800     YES
 RMS     Displacement     0.000587     0.001200     YES

vibration

wavenumber cm-1	521
symmetry	SGG
intensity arbitrary units	0
image

charge distribution

complex containing N₂

name:tris(m-N-(3,5-dimethylphenyl)di(propan-2-yl)phosphanaminido)-(bis(4-methoxyphenyl)methanone)-dinitrogen-titanium-cobalt diethyl ether solvate

N-N triple bond distance= 1.0773Å

The bond length between N-N triple bond in complex is smaller than that in nitrogen gas. This may because Co next to N donate electron to N, which results in the increase in electronegativity of that N atom, therefore the distance between two nitrogen atoms decreases.

energy for forming NH₃

E(NH3)=-56.55776873 a.u.

2*E(NH3)=-113.11553746 a.u.

E(N2)=-109.52412868 a.u.

E(H2)=-1.17853936 a.u.

3*E(H2)=-3.53561808 a.u.

ΔE=2*E(NH3)-[E(N2)+3*E(H2)]=-0.0557907 a.u. = -146.5 kjmol^-1

MO for Cl₂

This molecular orbital is the sigma bonding between two 1s orbitals of two chlorine atoms, which is deep in energy (-101.60295 a.u.) and occupied by two electrons.

This molecular orbital is the sigma antibonding between two 1s orbitals of two chlorine atoms, which is occupied by two electrons. This orbital is not deep in energy(-9.51828 a.u.).

This molecular orbital is the sigma bonding between two 2p orbitals of two chlorine atoms, which is occupied by two electrons. This orbital is not deep in energy(-7.2859 a.u.).

This molecular orbital is the pi antibonding between two 4p orbitals of two chlorine atoms, which is HOMO of Cl₂ and occupied by two electrons. This orbital is not deep in energy(-0.31356 a.u.).

This molecular orbital is the sigma antibonding between two 4p orbitals of two chlorine atoms, which is LUMO of Cl₂ and not occupied by electrons. This orbital is not deep in energy(-0.14189 a.u.).

Marking

Note: All grades and comments are provisional and subject to change until your grades are officially returned via blackboard. Please do not contact anyone about anything to do with the marking of this lab until you have recieved your grade from blackboard.

Wiki structure and presentation 1/1

Is your wiki page clear and easy to follow, with consistent formatting?

YES

Do you effectively use tables, figures and subheadings to communicate your work?

YES - well structured wiki good job.

NH3 1/1

Have you completed the calculation and given a link to the file?

YES

Have you included summary and item tables in your wiki?

YES

Have you included a 3d jmol file or an image of the finished structure?

YES

Have you included the bond lengths and angles asked for?

YES

Have you included the “display vibrations” table?

YES

Have you added a table to your wiki listing the wavenumber and intensity of each vibration?

YES

Did you do the optional extra of adding images of the vibrations?

YES

Have you included answers to the questions about vibrations and charges in the lab script?

YES

N2 and H2 0.5/0.5

Have you completed the calculations and included all relevant information? (summary, item table, structural information, jmol image, vibrations and charges)

YES

Crystal structure comparison 0.5/0.5

Have you included a link to a structure from the CCDC that includes a coordinated N2 or H2 molecule?

YES

Have you compared your optimised bond distance to the crystal structure bond distance?

YES - your reasoning is quite difficult to understand however you have recognised the discrepancy due to bonding in the complex.

Haber-Bosch reaction energy calculation 0.5/1

Have you correctly calculated the energies asked for? ΔE=2*E(NH3)-[E(N2)+3*E(H2)]

YES

Have you reported your answers to the correct number of decimal places?

YES

Do your energies have the correct +/- sign?

YES

Have you answered the question, Identify which is more stable the gaseous reactants or the ammonia product?

You have not answered the question.

Your choice of small molecule 2.5/5

Have you completed the calculation and included all relevant information?

YES

Have you added information about MOs and charges on atoms?

You included the charges but no explanation of why they are 0 on both atoms. Some of the MO analysis is good however you have misidentified several of the contributing AOs. The second MO is 2s not 1s and the 4th and 5th MOs are 3p not 4p AOs.

Independence 0/1

If you have finished everything else and have spare time in the lab you could: Check one of your results against the literature, or Do an extra calculation on another small molecule, or Do some deeper analysis on your results so far

No independent work.