Point Groups: Photosensitive Manganese Tricarbonyls

• identify symmetry elements

• assign point groups

Point Groups: Molecular Anions and the Extended Structure of Cs5AsP4Se12

• draw Lewis structures and assign formal charges

• learn the meaning of a nonstereochemically active lone pair

• assign the point group of a challenging molecule

• interpret layer-by-layer drawings of unit cells and demonstrate that the unit cell stoichiometry matches the empirical formula

IR Spectroscopy: Predicting the structures of rhodium carbonyl clusters

• assign point groups to multinuclear rhodium carbonyl clusters

• predict the number of IR-active CO stretching frequencies in bridging and terminal CO regions

Raman Spectroscopy of P-doped Sodium Silicide, Na4Si4

• write and reduce a representation for all molecular motion for the tetrahedral (Si4)4- anion

• predict the number of Raman-active vibrational modes for the tetrahedral (Si4)4- anion

• assign the observed Raman spectrum of Na4Si4 by considering the effects of a descent in symmetry from the idealized Td point group

IR and Raman Spectroscopy of Cobalt Boronyl Tetracarbonyl, Co(BO)(CO)4

• assign the point groups of 3 possible structures for Co(BO)(CO)4

• predict the number of IR and Raman-active CO stretching frequencies for a each structure

A molybdenum carbonyl group theory question

• assign the point group of two molybdenum isomers

• use CO and CN stretching frequencies to assign isomer structures

• use knowledge of electronic and steric effects to rationalize the formation of the two isomers

IR and Raman Spectroscopy of the Pentabromide anion

• write and reduce a representation for all molecular motion for the V-shaped (Br5)– anion

• predict the number of IR and Raman-active vibrational modes

• write and reduce a representation for the subset of stretching modes in the V-shaped (Br5)– anion

• predict how many peaks would appear in the Raman spectrum

Using Computational Chemistry to discuss backbonding to CO

(The Great Backdonation Challenge)

• explain the effect of changing the metal on the CO stretching frequencies of a metal carbonyl complex

• understand the role of σ and π donors/acceptors in modifying the amount of π backdonation into a trans CO ligand

• predict the degree of backdonation into a trans carbonyl that will be observed with an unfamiliar ligand

• perform DFT calculations to find the minima and vibrational frequencies of a molecule using WebMO/Gaussian

Molecular Orbitals and the Jahn Teller Distortion of XeF3- anion

• derive the MO diagram of [XeF3]–

• apply a structural distortion to achieve either a T-shaped or Y-shaped molecule and consider the symmetry and orbital overlap changes that occur on an energy correlation diagram.

• rationalize the most likely structure(s) of [XeF3]– considering the impact of both steric and electronic factors