New D-π-A chromophores incorporating (5,5-dimethylcyclohex-2-en-1-ylidene)- or (6-methyl-4H-pyran-4-ylidene)-malononitrile moiety

New D-π-A-type chromophores that simultaneously incorporate N,N -dimethylaminophenyl moiety as the terminal electron-donating group and either (5,5-dimethylcyclohex-2-en-1-ylidene)malononitrile (DCM-1) or (6-methyl-4 H -pyran-4-ylidene)malononitrile (DCM-2) unit as the terminal electron-withdrawing group were synthesized. Vinylene moiety and azo group served as the π-spacer. A comparative analysis of optical and electrochemical properties of the synthesized chromophores revealed that the replacement of the DCM-1 unit with the DCM-2 moiety led to chromophore band gap broadening and a decrease in the molar extinction coefficient value; while the replacement of the DCM-1 unit with the DCM-2 one in the chromophores bearing the vinylene π-spacers led to a sharp increase in the fluorescence quantum yield.