Excited state relaxation processes of crowned styryl dyes and their metal complexes

摘要

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 and fluorescence spectra of a styryl dyeare shifted to high frequency regions, its fluorescence quantum yield in the absence of photoisomerization is practically unchanged, and the rate constant of its temperature 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 crown cycle may proceed in the excited state. The trans-cis photoisomerization of styryl dyes and their metal complexes is a barrierless reaction.