摘要
在研究β-环糊精(简称β-CD)作为催化剂在水中氧化苯甲硫醚的反应中,发现产物苯甲砜可以较稳定停留在β-环糊精的空腔中。采用~1H-NMR、TG-DSC、FT-IR等各种表征方法对β-环糊精与苯甲砜的相互作用关系进行分析,发现在水相中β-环糊精与苯甲砜可以自发地形成结构稳定的包结物;其吉布斯函变△γG_m~θ(298K)为-21.109 kJ·mol^(-1),稳定常数Ka为5015。苯甲砜以摩尔比为1:1进入β-环糊精的内部空腔,产生与β-环糊精不同的圆二色谱和荧光光谱信息,结合FT-IR分析推测出苯甲砜从β-环糊精的小口径进入其空腔内部形成的包结物更为稳定。
In order to study the interaction between β-cyclodextrin and substrate or product, which is quite helpful for mastering chemical reaction mechanism promoted by β-cyclodextrin, β-cyclodextrin was used as catalyst for the oxidation of methyl phenyl sulfide in water, and it was observed that the oxidation product, methyl phenyl sulfone, can exist stably in the cavity of β-cyclodextrin and form inclusion. Various characterization methods including ^1H-NMR, TG-DSC and FT-IR were adopted to analyze the interaction between β-cyclodextrin and methyl phenyl sulfone. It shows that the stable inclusion of β-cyclodextrin and methyl phenyl sulfone with molar ratio of 1：1 can be automatically formed in water （the stability constant of the inclusion, Ka, is 5015 and the standard Gibbs function of molar reaction, △γG_m~θ（289K）, is -21.109 kJ·mol^-1）. The informations of inclusion characterized by circular dichroism and fluorescence spectrum are different from that of β-cyclodextrin obviously. FT-IR analysis exhibits that the inclusion formed by methyl phenyl sulfone entering from the narrow mouth of the β-is more stable than that formed by entering from the broad mouth.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2007年第3期460-466,共7页
Journal of Chemical Engineering of Chinese Universities
基金
国家自然科学基金(20576045)
新世纪优秀人才支持计划资助
关键词
Β-环糊精
苯甲砜
包结物
稳定常数
β-cyclodextrin
methyl phenyl sulfone
inclusion
stability constant
