Abstract：A new potential pharmaceutical compound, 2-(4-dimethylaminophenyl)-5-fluoro-6-(morpholin-4-yl)-1H-benzimidazole (4) was synthesized. The effect of the pH value of aqueous solution on the absorption spectrum of compound 4 and its interaction with β-cyclodextrin (β-CD) were investigated by UV-Vis spectrum, steady-state fluorescence and time-resolved spectroscopic measurements. The results indicate that compound 4 mainly exists in neutral molecular state when pH value of the aqueous phase is above 7.0. In the pH range from 7.0 to 3.8 the neutral molecular state and protonated univalent cationic form coexist. As the pH value decreases, the content of univalent cationic form increases. When 2.76＜pH＜3.8, the protonated univalent cationic form is the predominant species. With further decrease of the pH value, the univalent cation is protonated by another H+ to form a bivalent cation，and both univalent and bivalent cations coexist in the solution. The steady-state fluorescence and time-resolved spectroscopic measurements revealed that compound 4 is a sensitive molecular probe. The interaction of compound 4 and β-CD is very strong. The guest: host ratio of inclusion complex between compound 4 and β-CD formed in the aqueous solution (pH=9.50) is 1∶1，and the association constant was determined to be (1.02±0.04)×103 mol·L-1.
唐凌天，王祥云，刘新起，王 毅* . 2-对二甲氨基苯基-5-氟-6-吗啉苯并咪唑的合成及其光谱学性质研究 [J]. 光谱学与光谱分析, 2004, 24(05): 588-591.
TANG Ling-tian, WANG Xiang-yun, LIU Xin-qi, WANG Yi* . Synthesis of 2-(4-Dimethylaminophenyl)-5-Fluoro-6-(Morpholin-4-yl)-1H-Benzimidazole and Its Spectroscopic Research . SPECTROSCOPY AND SPECTRAL ANALYSIS, 2004, 24(05): 588-591.
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