Triplet–triplet absorption spectra and the spectra of the photoreduced states of Rhodamine B and Rhodamine 110

Abstract

Absorption spectra and extinction coefficients for triplet–triplet absorption in alcoholic solutions of Rhodamine B (R.B.) and Rhodamine 110 (R110) are presented, together with the quantum yields for production of the triplet states in solution and the first and second order rate constants for decay of triplet states in deaerated solutions. Absorption spectra for the semi-reduced forms of the dyes are also reported.