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作 者:曲秀葵[1] 孙德志[1] 郑文清[1] 刘敏[1] 魏西莲[1]
出 处:《物理化学学报》2007年第1期116-119,共4页Acta Physico-Chimica Sinica
基 金:山东省自然科学基金(2004zx15)资助项目
摘 要:在298.15K下用微量热法结合核磁共振法研究了α-环糊精,β-环糊精与十二烷基多氧乙烯磺酸钠C12EnS(n=1,3)在水溶液中的包结作用.实验结果表明,"-环糊精与客体的包合是焓、熵共驱的过程,α-环糊精与客体的包合则是焓驱动过程."-环糊精与两种客体包合的化学计量比随客体中氧乙烯链的不同而不同,而α-环糊精与两种客体包合的化学计量比则无差别.1HNMR数据表明,C12EnS的存在使两种环糊精上各质子的化学位移向高场移动,从微观上证明了包结作用的发生.The association of α-cyclodextrin (α-CD) and β-cyclodextrin (β-CD) with sodium polyoxyethylene dodecyl sulfonate (C12EnS, n=1, 3) was studied by means of isothermal titration calorimetry and ^1H NMR measurements in aqueous solution at 298.15 K. The results indicated that the binding processes ofβ-CD with the surfactants were characterized by both enthalpy favorable and entropy favorable, while those of α-CD with the surfactants were mainly entropy driven. The stoichiometry of β-CD binding with the surfactants varied with numbers of oxyethyl groups in surfactant molecules, while that of α-CD binding with the surfactants made no difference. The ^1H NMR spectra revealed that chemical shift data of all protons in α-CD and β-CD molecules moved to high field in the presence of C12EnS, which could be regarded as a microscopic evidence of the occurrence of inclusion interaction.
关 键 词:环糊精 ^1H核磁共振 包合物 微量热 十二烷基多氧乙烯基磺酸钠
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