Synthesis and characterization of a new chromophor with acid/base-sensitive fluorescence emission

A new two-photon absorption compound, 2-{4-[(dicyanomethylidene-5,5-dimethylcyclohexl)vinyl]phenyl}imidazo[4,5-f][1,10]phenanthroline (DDVPIP), was synthesized and characterized. The one-photon excited fluorescence (OPEF) and two-photon excited fluorescence (TPEF) of DDVPIP are sensitive to the acid/base of the solution, which are enhanced in basic solution but weakened in acidic solution. Charge-transfer (CT) states of DDVPIP were calculated through theory methods to explain its acid/base-sensitive fluorescent properties.