Photophysical and photochemical properties of HITC indotricarbocyanine dye molecules in solutions

Abstract

Results of studies on the photonics of HITC indotricarbocyanine dye molecules with I –, Br–, and ClO4– counterions were presented. Introduction of an additional salt (tetrabutylammonium bromide) (10–2 M) to slightly polar solutions of the tricarbocyanine dye was shown to cause signifi cant changes in the dye photophysical and photochemical characteristics. It was concluded based on a comparison of HITC dye photophysical properties with I –, Br–, and ClO4– counterions in slightly polar dichlorobenzene and highly polar EtOH; an analysis of trends in HITC photobleaching in deoxygenated and air-saturated solutions; and data from femtosecond spectroscopy that the features of the photophysical and photochemical processes in slightly polar dichlorobenzene were due to superfast charge transfer in tight ion pairs followed by formation of free radicals