单取代烷烃的熵和吉布斯自由能与分子结构的关系

The relation between the entropy and Gibbs free energy of monosubstituted alkanes and their molecular structure

将单取代烷烃RX(X=OH、SH、NH2、Cl、Br、I、NO2、CN等)分子结构分为两个区域R和X来提取分子结构参数,从三方面影响因素:烷基R、取代基X、R与X相互作用来定量关联RX标准摩尔熵及标准摩尔生成吉布斯自由能。获得了已有实验测定的单取代烷烃RX标准摩尔熵及标准摩尔生成吉布斯自由能,并以烷基的碳原子数、取代基X对所研究单取代烷烃热力学性质的贡献值,烷基的极化效应指数与取代基电负性的乘积三参数为变量,建立定量相关模型,采用留一法交叉验证这些方程,结果表明,模型方程都具有良好的稳定性和预测能力。

The molecular structure of monosubstituted alkane RX（X=OH,SH,NH2,Cl,Br,I,NO2,CN） was divided into two parts,R and X,and molecular structure parameters were obtianed.It was proposed that the standard molar entropy and standard molar Gibbs free energy of formation affected by three main factors for RX compounds,including alkyl group R,substituted group X,and interaction between R and X.Using three parameters,the number of carbon of alkyl R,the standard molar entropy and standard molar Gibbs free energy of formation of substituted group X,the product of polarizability affected index of alkyl and electronegativity of substituent.Quantitative structure-retention correlation models were obtained.The stability and prediction of above equations was tested by the leave-one-out cross-validation method.