化学学报 ›› 2004, Vol. 62 ›› Issue (13): 1247-1251. 上一篇    下一篇

研究论文

微量热法研究β-环糊精与3-烷氧基-2-羟丙基三甲基溴化铵的相互作用

孙得志, 王世兵, 魏西莲, 尹宝霖, 李林尉   

  1. 聊城大学化学化工学院, 聊城, 252059
  • 投稿日期:2003-06-06 修回日期:2004-01-02 发布日期:2014-02-17
  • 通讯作者: 孙得志,E-mail:sundezhisdz@163.com;dzsun@eyou.com;Fax:0635-8239121. E-mail:sundezhisdz@163.com

Study of Host-Guest Complexation between β-Cyclodextrin and 3-Alkoxyl-2-hydroxypropyl Trimethyl Ammonium Bromides in Aqueous Solutions with Microcalorimetry

SUN De-Zhi, WANG Shi-Bing, WEI Xi-Lian, YIN Bao-Lin, LI Lin-Wei   

  1. Department of Chemistry, Liaocheng University, Liaocheng 252059
  • Received:2003-06-06 Revised:2004-01-02 Published:2014-02-17

在298.15 K下用微量热法研究了β-环糊精与3-烷氧基-2-羟丙基三甲基溴化铵在水溶液中的包结作用.实验表明,随着疏水链CnH2n+1O中碳原子数目n的增加(n=8,12,14),主-客体包合物的化学计量比由1:1为主变为2:1为主.各包合物都比较稳定,对应于n=8,12,14所得实验稳定常数分别为: β1=1.08×10-3 dm3·mol-11=28.66×103 dm3·mol-12=141.9×103 dm6·mol-2.形成包合物的过程都是焓、熵共同驱动的过程.包合物标准形成焓(ΔH㈠)和标准形成熵(ΔS㈠)随着CnH2n+1O中碳原子数目n的增加而减小.从主、客体的微观结构及包合物形成前后表面活性剂离子周围溶剂分子排列结构的变化出发对实验结果进行了讨论.

关键词: β-环糊精, 3-烷氧基-2-羟丙基三甲基溴化铵, 微量热, 主-客体包合物

Interactions between β-cyclodextrin (β-CD) and 3-alkoxyl-2-hydroxypropyl trimethyl ammonium bromides (CnNBr), a new kind of surfactants synthesized in this laboratory, in aqueous solutions were investigated with titration microcalorimetry at 298.15 K.The results were discussed in the light of hydrophobic interaction of β-CD with CnNBr and the iceberg structure made up of water molecules around hydrophobic tail of the surfactant.Stoichiometry of the host-guest complex changes from 1:1 to 2:1 as the number of carbon atoms (n) in hydrophobic chain, CnH2n+1O, increases from 8 to 14.All the complexes are quite stable with the apparent experiential stability constants being β1=1.08×103 dm 3·mol-1, β1=28.66×103 dm3·mol-1 and β2=141.9×103 dm 6·mol-2, respectively for n=8, 12, 14.All the complexation processes are proved to be both enthalpy and entropy beneficial, and the standard thermal effect increases, while standard entropy change decreases, with the hydrophobic chain becoming longer.

Key words: β-cyclodextrin, 3-alkoxyl-2-hydroxypropyl, microcalorimetry, host-guest complex