Ensembles of rings with a coumarin unit. 2. Spectral luminescent properties and spin-orbit coupling in molecules of 3-(2-R-thiazol-4-yl)- and 3-(4-R-thiazol-2-yl)coumarins

Authors

  • А. O. Дорошенко Kharkov State University, Kharkov 310077
  • E. А. Посохов Kharkov State University, Kharkov 310077
  • Я. B. Белоконь Ukrainian Pharmaceutical Academy, Kharkov 310002
  • C. Н. Коваленко Kharkov State University, Kharkov 310077
  • B. B. Иванов Kharkov State University, Kharkov 310077
  • O. А. Пономарев Kharkov State University, Kharkov 310077

Abstract

We have investigated the luminescent spectral properties of 3-(2-R-thiazol-4-yl)coumarins (R=CH3, CH2CH, 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 degradation 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 π-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 π, π-type.

How to Cite
Doroshenko, A. O.; Posokhov, E. A.; Belokon', Y. V.; Kovalenko, S. N.; Ivanov, V. V.; Ponomarev, O. A. Chem. Heterocycl. Compd. 1997, 33, 1177. [Khim. Geterotsikl. Soedin. 1997, 1356.]

For this article in the English edition, see DOI https://doi.org/10.1007/BF02290866

Published

1997-10-25

Issue

Section

Original Papers