An investigation of the electronic structures of transition metal complexes by single crystal polarized spectroscopy

• Main Author: Cowman, Charles Dane
• Format: Others
• Published: 1974
• Online Access: https://thesis.library.caltech.edu/4246/1/Cowman_jr_cd_1974.pdf; Cowman, Charles Dane (1974) An investigation of the electronic structures of transition metal complexes by single crystal polarized spectroscopy. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/3FCT-A075. https://resolver.caltech.edu/CaltechETD:etd-10252005-091128 <https://resolver.caltech.edu/CaltechETD:etd-10252005-091128>

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. A technique for growing thin film single crystals using tetra-n-butylammonium as a cation is detailed. The polarizations of both ligand field and charge transfer transitions were measured at 5[degrees]K for a number of transition metal monomeric and dimeric species. The polarized spectra for the [...] square planar complexes [...] and [...] confirm the [...] nature of the charge transfer bands. Spin orbit coupling was found to be important. The d orbital ordering [...] was found. The absorption spectra of the planar chlorobridged species [...] and [...] were found to exhibit anomalously large intensities for the spin-forbidden bands in the in-plane direction perpendicular to the metal-metal axis. The observed splitting of the lowest spin allowed d-d transition confirms the existence of metal-metal interaction. The ligand field absorption spectra of the square pyramidal [...] and [...] species are dominated by the equatorial allowed [...], dyz transition. Progressions of the totally symmetric metal-nitrogen stretch are observed on the transition. The observation of an axial polarized double progression of the metal-halogen symmetric stretch requires the inclusion of spin orbit coupling. The d orbital ordering [...] is identical to that in vanadyl ion. The [...] transition in the quadruply bonded [...] and [...]. species has been positively identified by the MCD and polarization data in the [...] complexes, compared to the polarization of this band in the lower symmetry species [...]. Progressions of the totally symmetric metal-metal stretch characterize the band envelope. The related [...] and [...] species also contain an analogous temperature independent band. The applicability of the molecular orbital scheme proposed by Cotton was confirmed. The polarized spectra of the [...] anion suggest a [...] structure related to the [...] complex. The polarization of the absorption bands of [...] were distinctly different; this species is known to have a [...] confacial bioctahedral structure.