SPECTROSCOPIC INVESTIGATION OF CYANOVINYL-DIETHYLANILINE DYES IN SOLUTIONS

Dye solutions of 4-dicyanovinyl-N,N-diethylaniline (DCVA) and 4-tricyanovinyl-N,N-diethylaniline (TCVA) are analysed by absorption and fluorescence spectroscopy. At room temperature the fluorescence quantum yields are very small. Temperature dependent fluorescence quantum efficiency measurements of DCVA in methanol indicate an intrinsic barrierless S1-S0 relaxation of the dye molecules. The permanent dipole moments of the molecules in the ground state and excited state are estimated from spectral shifts of the absorption and emission spectra. © 1990.