Vol. 19, issue 02-03, article # 26

Abstract:

Results of investigation of influence of the four-biscyanine dyes chromophore interaction on triplet states and basic characteristics of the long-time luminescence are presented. The values of quantum yields of intercombination conversion S₁ ~ → T₁ for two biscyanines were determined by the pulse photolysis method. Based on the long-time luminescence spectra and kinetics measurements, the coefficients characterizing the efficiency of formation of triplet states of four biscyanine dyes were determined. It was found that increase of the S₁ electronic level splitting of biscyanines conditioned by the efficiency of chromophore interaction results in a decrease in the singlet-triplet splitting and, as a consequence, in increase of intercombination conversion quantum yield.