Construction of Molecular Orbital Diagrams
Watch the lecture video below.
MO Diagrams of Diatomic Molecules
Chemistry 107 Lecture 07
Explanation: A review of the first three "Basic Rules of MO Theory and a presentation of RULE 4: if AOs are non-degenerate, the bonding MO will be localized on the atom with the lower energy AO and the anti bonding MO will be localized on the atom with the higher energy AO. Simple homo-diatomic MO diagrams for period 2 is presented with a discussion of orbital mixing.
Video 1: YouTube video: https://www.youtube.com/watch?v=oPZ3jnLlwXE&list=PLqOZ6FD_RQ7kGnKLTbdwZ3IGVNXK43k7S&index=8, 49 minutes.
pdf Supporting Materials: Chemistry 107 lecture supplements: Diatomic MO Diagrams (7_Ch5_Diatomic MO Diagrams.pdf). The MO diagram for oxygen is presented as opposed to the Lewis description. Orbital mixing is presented as an explanation for the change in orbital energy positions between N2 and O2. Bond order and bond distance is qualitatively discussed and a simple hetero-diatomic example is presented, HF.
Analysis of Molecular Orbitals of sulfur hexafluoride: (DFT), (excel table) and (pdf version of excel table).
Test your understanding:
Construction of simple molecular orbital diagrams.
MO Diagram Quiz - "MO_Theory_NH3" (pdf)
MO Diagram Quiz Solution - "MO_Theory_NH3_soln" (pdf)
Worksheets:
MO part 2: MO Diagrams for Diatomic Molecules (pdf) (solutions)
Computational Exercises 3 & 4: Simple Bonding (pdf) (solutions)
Spartan files to accompany Computational Exercises 3 & 4
CE3 cyanide (HF/6-31G)
CE3 methyleneimine (HF/6-31G)
CE3 hydrogen cyanide (HF/6-31G*)
CE4 dinitrogen (HF/6-31G*)
CE4 dioxygen (HF/6-31G*)
CE4 carbon monoxide (HF/6-31G*)
CE4 NO+ (HF/6-31G*)
CE4 cyanide anion (HF/6-31G*)
Watch the lecture video below.
MO Diagrams of Larger Molecules 1 and 2
Chemistry 107 Lecture 08 and Lecture 09
Video 1 Explanation: (a) In the first 39 minutes, simple homo-diatomic MO diagrams for period 2 elements is presented with a discussion of orbital mixing with the change of orbital energy positions between N2 and O2 and includes a discussion of bond order and bond distance. (b) A recipe of how to generate sigma-bonding MOs for larger molecules based on reducing a reducible representation is described for the H3+ ion.
Video 1: YouTube video: https://www.youtube.com/watch?v=Zre4RrOYfjg&index=9&list=PLqOZ6FD_RQ7kGnKLTbdwZ3IGVNXK43k7S, 49.5 minutes.
Video 2 Explanation: The generation of MO diagrams for four "larger" molecules is presented by (i) inspection method, and (ii) by reducible representation method. The analysis is performed for linear H3+, FHF-, CO2, and H2O.
Video 2: YouTube video: https://youtu.be/GOO3gfjtV1Y?list=PLqOZ6FD_RQ7kGnKLTbdwZ3IGVNXK43k7S, 51 minutes.
pdf Supporting Materials: Chemistry 107 lecture supplements: Construction of MO Diagrams for larger molecules (8_Ch5_MO Diagrams Bent.pdf). The MO diagram for linear H3+, FHF-, CO2, and H2O is presented.
Test your understanding:
Construction of more sophisticated molecular orbital diagrams.
more MO Diagrams Quiz - "MO_Theory_SF4" (pdf)
more MO Diagrams Quiz Solution - "MO_Theory_SF4_soln" (pdf)
more MO Diagrams Quiz - "MO_Theory_XeF4" (pdf)
more MO Diagrams Quiz Solution - "MO_Theory_XeF4_soln" (pdf)
Worksheets:
MO part 3: MO Diagrams for Larger Molecules (pdf) (solutions)
Computational Exercise: MO Diagram for PF5 (pdf) (solution)
Spartan files to accompany PF5 MO diagram Computational Exercise
Spartan files to accompany Computational Exercise 6
CE6 diborane (DFT)
Computational Exercise 8: Nitroxyl (pdf) (solutions)
Spartan files to accompany Computational Exercises 8
CE8 singlet nitroxyl anion, NO- (DFT)
CE8 triplet nitroxyl anion, NO- (DFT)
CE8 singlet nitroxyl, HNO (DFT)
CE8 singlet NOH (DFT)
Computational Exercise 13: Benzene stacks (pdf) (solutions)
Spartan files to accompany Computational Exercises 13
Proficiencies:
construct molecular orbital diagrams
populate MO diagrams with electrons and identify HOMO amd LUMO orbitals
generate qualitative diagrams of molecular orbitals