NH₃ Optimisation

What is the calculation method? RB3LYP

What is the basis set? 6-31G(d,p)

What is the final energy E(RB3LYP) in atomic units (au)? -56.55776873

What is the RMS gradient? 0.00000485

What is the point group of your molecule? C3V

optimised N-H bond distance and the optimised H-N-H bond angle? 1.02 & 106

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
 Predicted change in Energy=-5.986295D-10

Jmol

NH3_Molecule_01574856

Link to completed NH₃ optimisation https://wiki.ch.ic.ac.uk/wiki/images/f/fe/TAMIM_RAHMAN_NH3_OPTIMISATION_POP.log

Display Vibrations

Display Vibrations Table

Wavenumber (cm^-1)	1090	1694	1694	3461	3590	3590
Symmetry	A1	E	E	A1	E	E
Intensity (a.u.)	145	14	14	1	0	0
Images

How many modes do you expect from the 3N-6 rule? 6
Which modes are degenerate (ie have the same energy)? 2&3 and 5&6
Which modes are "bending" vibrations and which are "bond stretch" vibrations? 1,2 and 3 are bending vibrations while 4,5 and 6 are bond stretch vibrations.
Which mode is highly symmetric? 4
One mode is known as the "umbrella" mode, which one is this? 11
How many bands would you expect to see in an experimental spectrum of gaseous ammonia? 3

Charge Distribution

The charge on nitrogen should be slightly negative whereas the hydrogen atoms will have a slightly positive charge. This is due to the difference in electronegativity, nitrogen is more electronegative than hydrogen and therefore has a higher electron density to it leading to its slightly negative charge.

N₂Optimisation

What is the calculation method? RB3LYP

What is the basis set? 6-31G(d,p)

What is the final energy E(RB3LYP) in atomic units (au)? -109.52412868

What is the RMS gradient? 0.00000060

What is the point group of your molecule? D*H

Optimised N-N bond distance? 1.11

Item Table

         Item              Value      Threshold  Converged?
 Maximum Force            0.000001     0.000450     YES
 RMS     Force            0.000001     0.000300     YES
 Maximum Displacement     0.000000     0.001800     YES
 RMS     Displacement     0.000000     0.001200     YES
 Predicted change in Energy=-3.400972D-13

Jmol

N2_molecule

Link to completed N₂ optimisation: https://wiki.ch.ic.ac.uk/wiki/images/c/c7/TAMIM_N2_1.LOG

DIsplay Vibrations

Display Vibrations Table

Wavenumber (cm^-1)	2457
Symmetry	SGG
Intensity (a.u.)	0
Images

How many modes do you expect from the 3N-6 rule? 0
Which modes are "bending" vibrations and which are "bond stretch" vibrations? Only 1 bond stretching vibration
Which mode is highly symmetric? 1

Charge Distribution

The charges on both Nitrogen atoms are zero as they have the same electronegativity which means there is no dipole in the diatomic moleule.

H₂ Optimisation

What is the calculation method? RB3LYP

What is the basis set? 6-31G(d,p)

What is the final energy E(RB3LYP) in atomic units (au)? -1.17853936

What is the RMS gradient? 0.00000017

What is the point group of your molecule? D*H

Optimised H-H bond distance? 0.74

Item Table

         Item               Value     Threshold  Converged?
 Maximum Force            0.000000     0.000450     YES
 RMS     Force            0.000000     0.000300     YES
 Maximum Displacement     0.000000     0.001800     YES
 RMS     Displacement     0.000001     0.001200     YES
 Predicted change in Energy=-1.164080D-13

Jmol

h2_molecule

Link to completed H₂ optimisation: https://wiki.ch.ic.ac.uk/wiki/images/d/d4/TAMIM_H2_1.LOG

Display Vibrations

Display Vibrations Table

Wavenumber (cm-1)	4466
Symmetry	SGG
Intensity (a.u.)	0
Images

How many modes do you expect from the 3N-6 rule? 0
Which modes are "bending" vibrations and which are "bond stretch" vibrations? Only 1 bond stretching vibration
Which mode is highly symmetric? 1

Charge Distribution

The charges on both Hydrogen atoms are zero as they have the same electronegativity which means there is no dipole in the diatomic moleule.

Mono-metallic Transition Metal Complex

The transition metal complex chosen was (dinitrogen)-(2,6-bis(1-(2,6-diisopropylphenylimino)propyl)pyridine)-iron with the reference code BARTOF.

The bond length of N₂in the molecule above is slightly higher than the bond length of N₂that was calculated before (1.112 compared ot 1.1055). This is due to the lone pair of one nitrogen being donated to the central Iron atom which lowers the electron density on the nitrogen atom; this leads to less overlap of orbitals leading to a higher bond length.

Link to journal: https://pubs.acs.org/doi/10.1021/ic202750n

Haber-Bosch Process

E(NH₃) = -56.55776873
2*E(NH₃) = -113.11553746
E(N₂) = -109.52412868
E(H₂) = -1.17853936
3*E(H₂) = -3.53561808
ΔE=2*E(NH₃)-[E(N₂)+3*E(H₂)] = -0.05579076

The product ammonia is more stable than the gaseous reactants as it has a lower energy than the reactants. This means it is more stable as the forward reaction is exothermic.

Own Molecule - SH₂

What is the calculation method? RB3LYP

What is the basis set? 6-31G(d,p)

What is the final energy E(RB3LYP) in atomic units (au)? -399.39162414

What is the RMS gradient? 0.00012068

What is the point group of your molecule? C2V

Bond angle of H-S-H? 92.681

Item Table

         Item               Value     Threshold  Converged?<br>
 Maximum Force            0.000175     0.000450     YES<br>
 RMS     Force            0.000145     0.000300     YES<br>
 Maximum Displacement     0.000386     0.001800     YES<br>
 RMS     Displacement     0.000386     0.001200     YES

Jmol

sh2_molecule

Link to completed SH₂ optimisation: https://wiki.ch.ic.ac.uk/wiki/images/f/f8/TAMIM_SH2.LOG

Display Vibrations

Display Vibrations Table

Wavenumber (cm^-1)	1224	2692	2712
Symmetry	A1	A1	B2
Intensity	5	7	9
Images

How many modes do you expect from the 3N-6 rule? 3
Which modes are "bending" vibrations and which are "bond stretch" vibrations? 1 is a bending vibration while 2 and 3 are bond stretch vibrations.
Which mode is highly symmetric? 2

Charge Distributions

The charge on Sulfur is slightly negative whereas the hydrogen atoms have a slightly positive charge. This is due to the difference in electronegativity, sulfur is more electronegative than hydrogen and therefore has a higher electron density to it leading to its slightly negative charge.

Molecular Orbitals


Bonding molecular orbital between 3s electrons from sulfur and 1s electrons from the hydrogen. It is also an occupied orbital and has an energy of -0.74654.	Non-bonding orbital consisting of the 2p orbital from the sulfur. Occupied orbital with energy of -5.91268.	Anti-bonding molecular orbital created between the 3p orbitals from sulfur and1 s orbitals from hydrogen. This is an unoccupied orbital with an energy of 0.02126.	Bonding molecular orbital whihc is created due to the 3p orbital of sulfur and 1s orbital from the hydrogens. This is an occupied orbital with an energy of -0.44963.	SP mixnig between the s and p orbitals of sulfur and also consists of molecular orbital being created between the p orbital of sulfur and s orbitals of hydrogen. This is an occupied orbital with an energy of -0.36725.

Marking

Note: All grades and comments are provisional and subjecct 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

NH3 0.5/1

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, however you claimed 3 band to be visible in the real spectrum without any discussion of this number. You correctly stated that there are two sets of degenerate modes - this explains a spectrum with 4 peaks. However there are only 2 peaks visible as peaks 4, 5 and 6 are of too low an intensity to be visible.

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

for linear molecules the 3N-6 rules does not apply! You should have used the 3N-5 use instead!

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

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 - however it was asked to report the energy in kJ/mol as well!

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

NO - calculated energies in atomic units should be quoted with 5-7 decimal places. You used 8 instead which is higher than the accuracy of the calculation.

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?

YES

Your choice of small molecule 4.5/5

Have you completed the calculation and included all relevant information?

YES

Have you added information about MOs and charges on atoms?

You have done a good job of presenting this information, well done! You correctly stated the energies of the MOs but haven't commented if they are lying low or high in energy (are they in the HOMO-LUMO region?)

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 - no independent work has bee identified

NH3 Optimisation

Item Table

Jmol

Display Vibrations

Display Vibrations Table

Charge Distribution

N2 Optimisation

Item Table

Jmol

DIsplay Vibrations

Display Vibrations Table

Charge Distribution

H2 Optimisation

Item Table

Jmol

Display Vibrations

Display Vibrations Table

Charge Distribution

Mono-metallic Transition Metal Complex

Haber-Bosch Process

Own Molecule - SH2

Item Table

Jmol

Display Vibrations

Display Vibrations Table

Charge Distributions

Molecular Orbitals

Marking

Wiki structure and presentation 1/1

NH3 0.5/1

N2 and H2 0.5/0.5

Crystal structure comparison 0.5/0.5

Haber-Bosch reaction energy calculation 0.5/1

Your choice of small molecule 4.5/5

Independence 0/1

NH₃ Optimisation

N₂Optimisation

H₂ Optimisation

Own Molecule - SH₂