Novel Fe3+ fluorescence probe based on the charge-transfer (CT) molecules

Abstract New kind of intermolecular charge transfer (CT) materials 4'-(4,5-diphenyl-4H-1,2,4-triazol-3-yl)-N,N-diphenyl-[1,1'-biphenyl]-4-amine ( T1 ), 4'-(3,5-diphenyl-4H-1,2,4-triazol-4-yl)-N,N-diphenyl-[1,1'-biphenyl]-4-amine ( T2 ) and4”-(4,5-diphenyl-4H-1,2,4-triazol-3-yl)-N,N-diphenyl-[1,1':4',1”-terphenyl]-4-amine ( T3 ) were synthesized, which composed of triphenylamine as the electron-donating group (D) and triazole derivatives as the electron-accepting group (A). T1 , T2 and T3 were used as Fe 3+ fluorescence sensor and show high selectivity and sensitivity to Fe 3+ . Furthermore, the possible fluorescence quenching mechanism is studied: the complexes formed between Fe 3+ and triazole derivatives of the CT molecules influence the intermolecular CT of T1 , T2 and T3 and then lead to the fluorescence quenching.