β-环糊精-有机膦酸包合常数及热力学参数的测定

Measurement of Binding Constants and Thermodynamic Parameters of β-Cyclodextrin-Phosphonic Acid Inclusion Compound

用紫外-可见光谱法测定了包合温度为30℃时,β-环糊精与PBTCA(2-磷酸基-1,2,4-三羧酸丁烷)、HEDP(羟基乙叉二膦酸)包合物的包合常数分别为:658.0、349.7,包合物的稳定性较弱。并根据在30℃、40℃、45℃、50℃下测得的包合常数,结合Van't Hoff方程计算出包合过程热力学参数△H,△S和△G均为负值,表明包合反应是放热反应且能自发进行,焓变是形成包合物的主要驱动力。

The binding constants of β-Cyclodextrin with PBTCA, HEDP is 658.0, 349.7, respectively, determined by fluorescence spectrometry at 30 ℃, the stability of inclusion compound is poor. The binding constants at 30℃, 40℃, 45 ℃ 5 0℃were obtained and the enthalpy change AH, entropy change AS, Gibbs f ree energy AG, were calculated by Van＇t Hoff formulae. AH, AS and AG were negative, suggesting that the inclusion interaction was exothermic and spontaneously, enthalpy is the main driving force.