对、间位卤代苯甲酸在水-乙醇混合溶剂中电离过程的焓、熵贡献  

Enthalpic and Entropic Contributions to the Ionization Process of m-and p-Halobenzoic Acids in Water-Ethanol Mixtures

作　　者：南延青[1] 林瑞森[1] 俞庆森[1] 

机构地区：[1]浙江大学化学系,杭州310027

出　　处：《化学学报》1997年第8期755-760,共6页Acta Chimica Sinica

基　　金：高等学校博士学科点专项基金资助项目

摘　　要：用LKB-2277 BioAtivity Monitor测定了25℃时间氯、对氯和对氟苯甲酸在水-乙醇混合溶剂中的标准电离焓,计算了相应体系的标准电离熵.利用Hammett方程对溶剂中酸的取代基常数σ进行了计算,求取了对应的焓、熵取代基常数σ_H和σ_S值及熵反应常数ρ_S,利用内部-环境模型和上述常数对溶剂效应和取代基效应进行了解释.The ionization enthalpies of m - Cl, p - Cl and p - F Benzoic acids were measured byLKB-2277 Bioactivity Monitor at 25℃ in water- ethanol mixtures. In the same solution, thecorresponding ionization entropies were calculated. The substituted constants σ were calculated according to Hammett Equation, the corresponding enthalpic constants, entropic constants and entropic reaction constants were also calculated. The effects caused by solvent and substituent were explained by the interaction between solute and solvent, and by the above constants.

关 键 词：电离焓 电离熵 氯苯甲酸 氟苯甲酸 

分 类 号：O625.53[理学—有机化学]