OPTICAL PROPERTIES OF $^{3}(n\Pi^{*})$ BEHZOPHENONES IN 4,4-DIBROMODIPHENYLETHER HOST CRYSTALS
Loading...
Date
1978
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
A variety of optical and zf ODMR experiments have been performed on the lowest $(n \Pi^{*})$ triplet states of benzophenone $(BP-h_{10})$, perdeutero-benzophenone $(BP-h_{10})$, and $4,4{^{\prime}}$-dibromobenzophenone (4,4 -DBBP) in single crystals of $4,4^{\prime}$ -dibromodiphenylether (DDE) at $1.4^{\circ}\,K$. The data include single-sublevel phosphorescence spectra and amplitude - modulated zf ODHR excitation spectra. The results are analyzed to determine the mechanisms responsible for the population and depopulation of the spin sublevels. A localized model suffices for triplet $BP-h_{10}$ in which the $T_{z}$ sublevel is moat active. Deuterium substitution has only a small effect on the radiative and nonradiative properties of $^{3}(n\pi)$ BP. In contrast, bromine substitution has a large and selective effect; this is a consequence of n and $\Pi$; electron delocization. Second-order vibronic contributions are important for the totally symmetric C = O stretching bands in the $4,4^{\prime}$ DBBP phosphorescence spectra.
Description
Author Institution: Department of Chemistry, University of Pittsburgh