Si. Druzhinin et al., EXCITED-STATE RELAXATION PROCESSES OF CROWNED STYRYL DYES AND THEIR METAL-COMPLEXES, Proceedings of the Indian Academy of Sciences. Chemical sciences, 107(6), 1995, pp. 721-727
The fluorescence of novel crowned styryl dyes and their complexes with
sodium cation was studied. The fluorescence quantum yield of crowned
styryl dye is higher than that of non-crowned ones. While absorption a
nd fluorescence spectra of a styryl dye are shifted to high frequency
regions, its fluorescence quantum yield in the absence of photoisomeri
zation is practically unchanged, and the rate constant of its temperat
ure fluorescence qienching rises as it forms a complex with the metal
ion. The relaxation processes of photoisomerization and recoordination
are considered. The adiabatic change of metal ion coordination in cro
wn cycle may proceed in the excited state. The trans-cis photoisomeriz
ation of styryl dyes and their metal complexes is a barrierless reacti
on.