Electronically asymmetric triphenylmethane dyes. Half-methoxy analogues of Malachite Green

New fluorescent dyes of interest as red light emitters for electroluminescence devices were synthesized by the condensation of diaminomaleonitrile and 2,5-diamino-3,6dicyanopyrazine with arylaldehydes. Substituent effects on their absorption and fluorescence spectra in the solution were determined by comparison with the parent chromophoric system. Their solid state absorption and fluorescence properties were evaluated with respect to their optimized molecular structures obtained by MOPAC methods.