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2002 analytical chemistry, review analytical chemistry, review Z 0400 37 -298 Radiationless Deactivation of the Excited Phototautomer Form and Molecular Structure of ESIPT Compounds --(DOROSHENKO, ANDREY O.; POSOKHOV, EUGENE A.; VEREZUBOVA, ALLA A.; PTYAGINA, LYDIA M.; SKRIPKINA, VALENTINA T.; SHERSHUKOV, VIKTOR M.; Photochem. Photobiol. Sci. 1 (2002) 2, 92-99; Dep. Chem., Kharkov State Univ., Kharkov 310077, Ukraine; EN)

We have investigated the luminescent spectral properties of 3- (2-R-thiazol-4-yl)coumarins (R = CH 3, CHeCN, Ar) and some isomeric 3-(4-R-thiazol-2-yl)coumarins (R = Ar) with substituents of different electronic types both in the coumarin and in the aryl moieties. We have obtained estimates of the rate constants for primary photophysical processes: emission of fluorescence and nonradiative degrtdation of the electronic excitation energy. We have calculated the matrix elements for the spin-orbit coupling operator, and based on these matrix elements we have calculated the intersystem crossing rate constants. We have shown that deterioration of the fluorescent properties of the studied thiazolyl derivatives of coumarin when 1r-conjugated moieties are introduced into the thiazole ring is determined by the enhancement of the spin-orbit interaction in a system of levels of the 7r, 7r-type.*For communication 1, see [1].

DOROSHENKO, A. O.; POSOKHOV, E. A.; BELOKON', YA. V.; KO-VALENKO, S. N.; IVANOV, V. V.; PONOMAREV, O.