Synthesis And Properties Study On New ESIPT Compounds

2-(1H-benzo[d]imidazol-2-yl) phenol compounds are a class of great research value of the fluorescent substance, which have become a new research study in the field of new type fluorescent probe. 2-(1H-benzo[d]imidazol-2-yl) phenol compounds are strong fluorescence intensity, high fluorescence quantum yield and large Stokes shift, so the application prospect is very wide, and studied by many domestic and foreign scholars. With the deepening and improvement of the study, some fluorescence probes have been commercialized abroad and played an important role in the medical diagnosis.This paper consists of two parts.In the first part, 2-(1H-benzo[d]imidazol-2-yl) phenol derivatives were synthesized, and their structures, tautomer and fluorescent properties were measured. The relationship of fluorescent characteristics and the substitutive groups were discussed, and the quantum yields were minished by the substitutive groups of attractive electrons. Fluorescence changes are investigated by the different metal ions and the fluorescence quenching of copper (â…¡) is the strongest, in the pH range of body, fluorescence intensity changes are flat relatively.In the second part, five water-soluble fluorescence probe of copper(â…¡) were synthesized, and their structures and fluorescent properties were measured. The relationship of fluorescent characteristics and the copper (â…¡)were discussed, and the copper(â…¡) of fluorescence quenching effect were discussed too. As the copper (â…¡) was increased in the concentration, the fluorescence intensity of various compounds gradually weakened, and even complete quenching of fluorescence. In the fluorescent nature, fluorescence quantum yield of the compound c was the largest, reaching 0.453; stokes shift of compound d was the largest, which was 147 nm. The solubility of compound e was the best, which was 0.21 g, moreover in the water the fluorescence intensity was very strong, in terms of acid-base, the fluorescence intensity are not the same in the same pH solution because of the differences in the number of hydroxyl group.