Спектральные проявления образования ионных пар индотрикарбоцианиновых красителей

Abstract

The changes in absorption and emission spectra due to the formation of ion pairs in indotricarbocyaninc dye TICS with Br anion and its cationic analog with BF4" anion in ethanol, methylene chloride, dichlorobenzene have been studied. It has been found that on going to low-polarity solvents the formation of ionic pairs is exhibited no only by electronic absorption and emission spectra, but also by excitation spectra and fluorescence anisotropy. It has been first found that excitation and polarization spectra of fluorescence reveal considerable changes in the spectral region associated with short wavelength absorption bands: upon heating a decrease of the fluorescence quantum efficiency is less pronounced and is associated with higher wavelength emission centers.