RESONANCE RAMAN SPECTRAL STUDIES OF COORDINATION COMPOUNDS CONTAINING SINGLE AND MULTIPLE CHROMOPHORIC GROUPS
Abstract
One of the most interesting features of resonance Raman (RR) spectroscopy is the selectivity of resonance enhancement; only those vibrations which are localized on a particular chromophoric group are enhanced when the energy of the exciting line approaches that of the electronic transition which originates in this chromophore. This dissertation reports RR spectra of various coordination compounds containing single or multiple chromophoric centers in one molecule and demonstrates the utility of RR spectroscopy in assigning their electronic spectra. Initial studies involve such compounds as; "red" and "black" K(,2){Ni(dto)(,2)} (dto; dithiooxalato anion), (H,H,Me)VOCuBr(,2)(.)CH(,3)OH ((H,H,Me); N,N'-bis(salicydene)propylenediamine), and Ni(S(,2)N(,2)H)(,2), each of which contains a single chromophore. Two series of overtones were observed in the RR spectra of "red" K(,2){Ni(dto)(,2)} in the solid state; (eta)(,1)(nu)(,1) ((nu)(,1) = 1085 cm('-1), (nu)(C-C) + (nu)(C-S)) progression up to (eta)(,1) = 6 and the (eta)(,1)(nu)(,1) + (nu)(,2) ((nu)(,2) = 1602 cm('-1), (nu)(C=O)) progression up to (eta)(,1) = 4. Using these progressions, the harmonic wavenumber and anharmonicity constants were calculated for (nu)(,1). Excitation profile studies of two totally symmetric vibrations ((nu)(,1) and (nu)(,4)(Ni-S stretch)) of both forms reveal the presence of three electronic transitions in the visible region. The (H,H,Me)VOCuBr(,2)(.)CH(,3)OH binuclear complex shows selective Raman intensity enhancement of the V-O(phenolic) stretching mode (647 cm('-1)) in resonance with the electronic band at 558.7 nm. This selective enhancement has been used in assigning this band to the V-O(phenolic) charge-transfer (CT) transition as previously suggested. The RR spectra of Ni(S(,2)N(,2)H)(,2) in the solid state show selective enhancement of N(,1) S(,1) (984 cm('-1)) and Ni-S(,2) (319 cm('-1)) stretches in resonance with a CT band at 570 nm. In contrast, the resonance behavior near the 400 nm band shows enhancement of the Ni-N(,1) stretch (35(TURN)40%) coupled with ligand bending modes. . . . (Author's abstract exceeds stipulated maximum length. Discontinued here with permission of school.) UMI
Recommended Citation
CZERNUSZEWICZ, ROMAN STANISLAW, "RESONANCE RAMAN SPECTRAL STUDIES OF COORDINATION COMPOUNDS CONTAINING SINGLE AND MULTIPLE CHROMOPHORIC GROUPS" (1981). Dissertations (1962 - 2010) Access via Proquest Digital Dissertations. AAI8211433.
https://epublications.marquette.edu/dissertations/AAI8211433