Van Stappen, Casey Michael2014-02-032014-02-032013-09https://hdl.handle.net/11299/162407University of Minnesota M.S. thesis. September 2013. Major: Chemistry. Advisor: Victor V. Nemykin. 1 computer file (PDF); vii, 202 pages.The UV-Vis and magnetic circular dichroism (MCD) spectra of the d1 oxomolybdenum tetrachloride ([MoOCl4]-) anion in C4v symmetry have been calculated using the ab initio complete-active-space self-consistent-field (CASSCF)/multi-reference configurational interaction (MRCI) theory. The influence of active space used in these calculations was investigated, and the use of a differential treatment of charge-transfer and ligand-field type transitions through partitioning of active space was found to be effective. Additionally, the influence of Hartree-Fock exchange on the vertical excitation energies of [MoOCl4]- has been investigated through DFT/TDDFT methods. The combined results provide a promising direction for the prediction of MCD spectroscopy in oxomolybenal complexes. The mixed-valence properties of aromatic polyferrocenyl heterocycles have received considerable attention in recent years due to their model properties for electronic intercommunication. While α, β, and α-β saturated ferrocenyl pyrroles have been synthesized and characterized, current studies of these complexes have lacked a theoretical investigation of their electronic properties. In this study, these complexes are characterized using TDDFT methods, and their mixed-valence states explored in order to provide insight to the first oxidation process of 2,3,4,5-tetraferrocenyl-pyrrole.en-USElectron correlationMixed-ValencyMulti-reference configuration interactionOxomolybdenumTDDFTThesis or Dissertation