Time-resolved EPR and ODMR studies on the lowest excited triplet states of α-silyl and α-germyl ketones
Autor: | Kunio Mochida, Seigo Yamauchi, Masamoto Iwaizumi, Masahiro Mukai, Noboru Hirota, Masanobu Wakasa, Minoru Hanaya, Islam S. M. Saiful |
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Rok vydání: | 2001 |
Předmět: | |
Zdroj: | Molecular Physics. 99:1183-1192 |
ISSN: | 1362-3028 0026-8976 |
Popis: | Sublevel properties of the lowest excited triplet (T1) npstates of ¬-silyl and ¬-germyl ketones were examined by means of ODMR, time-resolved EPR and optical spectroscopy. The EPR parameters, D, E and g, population ratios, and triplet lifetimes were obtained. The D value and the triplet lifetime varied among the molecules. In contrast the E value and population ratio remains nearly the same. These properties together with their solvent dependence and emission properties are interpreted in terms of spin± orbit couplings between T1 (np ¤ ) and higher S1 (np ¤ ), T2 (pp ¤ ) and S2 (pp ¤ ) states. An origin of the remarkable red-shifts of 1;3 (np ¤ ) are discussed based on a model of delocalized n, p and pelectrons over the Si and Ge atoms. This model is also consistent with all the triplet properties obtained. |
Databáze: | OpenAIRE |
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