Joint spectroscopic and theoretical investigation of cationic cyanine dye Astrazon Orange-R: solvent viscosity controlled relaxation of excited states

Abstract

In this paper, the first study of cationic cyanine dye Astrazon Orange-R by combined spectroscopic and theoretical investigation is presented. It is shown that molecular modeling of Astrazon Orange-R is in very good agreement with experiment, allowing us to gain insight into its complicated photophysics. A solvent viscosity controlled relaxation of excited states, involving cyanine isomerization, is also outlined.