Photochemistry of 3,4,9,10-perylenetetracarboxylic dianhydride dyes: visible absorption and fluorescence spectra and fluorescence quantum yields of the mono( n-octyl)imide derivative in aqueous and non-aqueous solutions

Abstract

This study characterizes the visible absorption and fluorescence spectra and fluorescence quantum yields of the dicarboxylate, dicarboxylic acid and anhydride forms of the mono( n-octyl)imide derivative of 3,4,9,10-perylenetetracarboxylic dianhydride in aqueous micellar and organic solvent media. All three forms of the mono( n-octyl)imide dye have primary visible absorption maxima in the range 495 – 530 nm, with extinction coefficients of (3 – 8) ×10 4M −1 cm −1 and fluorescence maxima in the range 520 – 600 nm, with quantum yields of 0.5 – 1.0. Vibrational structure in the absorption and fluorescence spectra increases and the Stokes loss decreases in the sequence dicarboxylate &>; dicarboxylic acid &>; anhydride. The dicarboxylic acid form of the dye dehydrates and cyclizes smoothly to the anhydride form in sodium dodecylsulfate micellar solutions with first-order kinetics and a half-time of 7 × 10 −5 s −1 (24 °C).