摘要
采用稳态和瞬态荧光法对2-(2-羟苯基)苯并噻唑(HBT)与七元瓜环(CB7)的超分子作用及CB7分子纳米腔限制作用对HBT激发态质子转移(ESIPT)过程进行了研究,并采用Benesi-Hildebrand方程对荧光数据进行处理,以确定超分子复合物的组成比.结果表明,在N,N-二甲基甲酰胺(DMF)和二氯甲烷溶液中,CB7与HBT的作用均形成化学计量比为1∶1的主客体复合物,HBT的质子转移对溶剂很敏感,CB7的加入,使HBT的荧光寿命降低,量子产率增大.在DMF溶液中,CB7的加入促进了酚氧负离子的形成,而在二氯甲烷溶液中,CB7的加入限制了HBT的激发态质子转移.结构优化计算表明,CB7与HBT能形成化学计量比为1∶1的复合物.
Proton transfer as one of the basic reaction exists in a large variety of chemical and biochemical process. And the organic molecules that exist the proton transfer process offten existence potential applications in biological and chemical industry. In this work,the supramolecular interaction of 2-（ 2-hydroxyphenyl）benzothiazole（ HBT） with different concentrations cucurbit[7]uril（ CB7） and its influences on the exited state intramolecular proton transfer（ ESIPT） of HBT were studied with stead-state and transient fluorescence spectra in the different solvents. Furthermore,the inclusion ratio of CB7 and HBT were obtained according to BenesiHildebrand equation based on the fluorescence data. The results show that the stoichiometric ratio 1 ∶ 1 hostguest complex of CB7 with HBT is formed in the N,N-dimethyeformamide（ DMF） or dichloromethane solution,and the proton transfer of HBT is very sensitive to solvent. When the concentration of CB7 was increased,the fluorescence lifetime and quantum yield of HBT were decreased and increased respectively. The phenolic oxygen negative ion was formed in DMF,and the ESIPT of HBT was decreased in dichloromethane. The quantum chemical calculations show that CB7 can form the 1 ∶ 1 HBT@ CB7 complexes for the enol or keto tautomer of HBT.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2015年第4期654-659,共6页
Chemical Journal of Chinese Universities
基金
国家自然科学基金(批准号:21172066,20971041)
湖南省高校科技创新团队项目(批准号:湘教通[2012]318)资助~~
