阳离子表面活性剂胶团催化的活化热力学参数  

Thermodynamic Parameters of Activation for Hydrolysis of 2,4-Dinitrochlorobenzene Catalyzed by Cationic Micelles

作　　者：赵振国[1] 沈吉静[1] 马季铭[1] 

机构地区：[1]北京大学化学与分子工程学院,北京100871

出　　处：《化学学报》2003年第2期298-302,共5页Acta Chimica Sinica

基　　金：国家自然科学基金 (No.2 97331 1 0 )资助项目

摘　　要：测定了在 9种阳离子表面活性剂胶团溶液中 2 ,4 二硝基氯苯 (DNCB)碱性水解的速率常数 ,计算了这些过程的活化热力学参数 .结果是 :( 1)DNCB在阳离子表面活性剂胶团溶液中碱性水解反应的活化自由能ΔG≠ 均比在纯水中降低 .( 2 )活化焓ΔH≠ 和活化熵ΔS≠ 显著降低 .( 3)活化熵ΔS≠ 均为负值 ,活化熵的降低对ΔG≠ 的减小不利 .( 4)胶团催化反应速率常数的变化主要是由ΔG≠ 决定 ,ΔG≠ 是ΔH≠ 和ΔS≠Apparent rates of hydrolysis of 2,4-dinitrochlorobezene (DNCB) catalyzed by nine cationic surfactants were determined and the thermodynamic parameters of activation were calculated. The results indicate that: (1) The free energies of activation, ΔG ≠, for hydrolysis of DNCB in the solutions of cationic surfactants are lower than those in water. (2) The enthalpies of activation, ΔH ≠, and the entropies of activation, ΔS ≠ are reduced by the cationic micelles. (3) The entropies of activation, ΔS ≠, are negative, which is favorable for the presence of more stable activation complex. (4) The rates of hydrolysis of DNCB is decided by ΔG ≠. The compensation effect of enthalpy-entropy has been envisaged.

关 键 词：阳离子表面活性剂 胶团催化 2 4-二硝基氯苯 水解 速率常数 化学动力学 热力学参数 活化自由能 

分 类 号：O647[理学—物理化学]