摘要
利用(经分光光度法实现的)相溶解法测定了稀水溶液中β-环糊精(β- CD)对偶氮苯的增溶等温线,从而求出了 1: 1配合物形成过程的热力学函数( k0,△ rG0,△ rH0,△ rS0) .结果表明 :β- CD能明显提高偶氮苯在水中的溶解度,并且随着β- CD的浓度增加,偶氮苯在水中的溶解度线性增大 .这是因为 1: 1配合物的稳定常数相当大,偶氮苯在纯水中的溶解热是 26.18kJ/mol,从固相偶氮苯直接变成配合物的过程则放出热量 4.22kJ/mol.所以β- CD和偶氮苯的配合过程是焓驱动过程 .
Thermodynamics of host- vip complexation of - cyclodextrin with Azo Benzene in dilute aqueous solution has been determind using spectrophotometry.The data show that - cyclodextrin(- CD) can increase the solubility of Azo Benzene in water and the solubility linearly increase with the rising of concentration of cyclodextrin. Since the 1:1 complex compound is very stable,the dissolving process of Azo Benzene changes from endothermic reaction in pure water(26.18KJ.mol- 1) to exothermic(4.22KJ.mol- 1) reaction in solution of - CD The homophase complex process of - CD with Azo Benzene is an enthalpy- driven one.
出处
《淄博学院学报(自然科学与工程版)》
2000年第3期58-60,共3页
Journal of Zibo University(Natural Sciences and Engineering)