Photophysical studies of acridine(1,8)dione dyes: a new class of laser dyes

The acridinedione dyes have been known as efficient laser dyes. A study of the photophysical processes is required to understand the charactersitics and identify better lasing dyes in the class. The absorption and fluorescence characteristics of the dyes have been studied. The fluorescence quantum yields are high due to the fairly rigid structure and the substitution on the nitrogen and in the 9-position are found to alter the quantum yields. The non-radiative rate constants are higher when substituted by aryl groups in the 9-position and on the nitrogen. The triplet-triplet absorption maxima and the triplet lifetime show variation depending on the substitution. (C) 1998 Elsevier Science B.V. All rights reserved.