摘要
以荧光发射光谱,1H NMR谱及量子化学计算研究了2-(3-乙酰胺基-2-吡啶基)苯并咪唑(2-3Am2PyBI)质子转移过程及其与七元瓜环超分子(CB7)的包合作用,考察了乙酰基取代基效应及CB7的包合作用对2-3Am2PyBI质子转移过程的影响.结果表明:乙酰基取代促进了质子转移过程;2-3Am2PyBI阳离子构型更易与CB7发生包合作用;在特定溶液pH值条件下,摩尔比法荧光光谱实验表明超分子包合作用抑制了2-3Am2PyBI的激发态质子转移过程;Benesi-Hildebrand方程拟合得到,超分子体系的包合比为1∶1;1H NMR测试进一步表明2-3Am2PyBI以苯环部分进入CB7的空腔,同时,以量化计算与荧光实验结合,从理论与实验方面共同验证了2-3Am2PyBI的质子转移异构体.
The interaction of2-（3-acetamido-2-pyridyl）-benzimidazole （2-3Am2PyBI） with cucurbit[7]uril （CB7） macrocycle and the effect of inclusion on the proton transfer of 2-3Am2PyBI were studied by using emission fluorescence, 1H NMR spec- tra and quantum chemical calculation. By the way, the proton transfer of the dye with and without acetyl （2-3A2PyBI） was also studied. The results indicate that the acetyl promoted the process of proton transfer of the benzimidazole and the cationic form binds with CB7 easier than the other forms of the dye. The fluorescence studying at selected pHs suggest that the proton transfer process of the dye was retarded by interacting with CB7 nanocavity and the molar rate is host vip= 1 ： 1 analyzed by the Benesi-Hildebrand method. The dye entered into the CB7 cavity with its benzene ring was proved by the 1H NMR titra- tion experiment and the protonated forms were verified by the quantum calculation with fluorescence spectra.
出处
《有机化学》
SCIE
CAS
CSCD
北大核心
2013年第7期1451-1456,共6页
Chinese Journal of Organic Chemistry
基金
国家自然科学基金(Nos.21172066
20971041)
湖南省自然科学基金(Nos.10JJ4011
11JJ2007)
湖南省高校科技创新团队支持计划(No
[2012]318-17))资助项目~~
关键词
质子转移
七元瓜环
荧光发射光谱
1HNMR谱
量化计算
proton transfer
cucurbit[7]uril
emission fluorescence
1H NMR spectra
quantum calculation
