Abstract

Dymethylaminobcnzylidene-1,3-indandione (DMABI) molecules in solutions show low quantum yield of fluorescence, short excited state life-time and unusual absorption and fluorescence spectra dependencies on solvent polarity and polarizability. It indicates photochemical reactions to take place in an excited state. DMABI molecule has 2.27 D dipole moment in a ground state which increases up to 14.22 D in an excited state. DMABI molecule is formed from two chromophoric fragments 1,3-indandione and dymethylaminobenzene connected via a CH bond. The later part is similar to the dimethilaminobenzonitrile molecule, which is well known from dual fluorescence investigations. DMABI molecule has two bonds where excited state isomerization can take place, i.e. rotation through the two fragments connecting CH-C bond and rotation of the dimethylamino group like in dimethilaminobenzonitrile.

© 1996 IEEE