Synthesis and photophysical properties of novel nicotinonitrile-based chromophores of 1,4-diarylbuta-1,3-diene series

Facile approach to the synthesis of novel donor-acceptor chromophores containing a 1,4-diarylbuta-1,3-diene system was developed. Optical properties of compounds in various solvents and in solid state were studied. It was found that compounds with unsubstituted and methoxy-substituted phenyl moiety conjugated with 2-amino-6-chloropyridine-3,5-dicarbonitrile acceptor show moderate photoluminescence in powders and weak emission in solution. At the same time, the presence of dimethylamino group in the phenyl moiety led to stronger intramolecular charge transfer (ICT) emission of the chromophore in many organic solvents and amorphous solids as well as to interesting acidochromic properties.