Synthesis and spectroscopic properties of conjugated triphenylamino-substituted chromophores

Two kinds of intramolecular conjugated charge-transfer triphenylamino-substituted chromophores 4-[2-(3-dicyanomethylene-5,5-dimethylcyclohex-1-enyl)-vinyl]triphenylamine (BHT) and 4,4′-bis[2-(3-dicyanomethylene-5,5-dimethyl-cyclohex-1-enyl)vinyl]triphenylamine (BDHT) were synthesized and characterized using 1H NMR, FTIR and elemental analysis. Their spectroscopic properties were studied in solution and in MTES-, VTES-derived bulk materials. It was found that the chromophore with symmetrical structure (BDHT) enhanced fluorescence quantum yield more than that of the chromophore with asymmetrical structure (BHT). The solvatochromic behaviour of the chromophores in different solvents indicates that the peak wavelength of their solution fluorescence spectrum is related linearly to the solvent polarity ET (30) in the cases of certain solvents.