Draw a molecular orbital diagram for CN-, indicating u and g symmetry notation. Assume σ and π order consistent with C2 and N2 diatomic molecule MO diagrams. Calculate the bond order for CN- and determine its magnetic properties.

4. The following phosphorous halide molecules contain P as the central atom. i. Draw the expected molecular shape, determine whether it is polar, and indicate the overall direction of the dipole moment. (You do NOT need to show resonance or formal charges AND if there are more than one isomer, please pick one for your answer ii. List all its symmetry elements and show all unique symmetry elements that are not the identity operator or an improper rotation. iii. Determine its point group. а. POCI3 b. РОCІBrz С. РOСІBrl

Sketch the MO diagram for 1,3 budadiene. Identify the HOMO and LUMO along with all symmetric MO’s, asymmetric MO’s, bonding MO’s, and anti bonding MO’s.

e. What are the characters for the irreducible representations for E"? f. If one O atom is placed in a D3h point group, what is the Mulliken symbol for its px orbital? g. If an Co²+ ion is placed in a D3h point group, what is the Mulliken symbol for its dxz orbitals? 4. One application of the Group Theory in chemistry is to predict vibrational modes of a molecule. For example, Mn(CO)5Cl (shown below) only gives one IR band. By answering the following questions, you will be able to understand why this is the case. OC-Mn- СО OC a. What is the point group of this molecule? b. Copy the Character Table for the identified point group from your textbook (Appendix C) here.