单取代烷烃的热容、熵和吉布斯自由能的定量估算  

Quantitative estimation of heat capacity,entropy and gibbs free energy of monosubstituted alkanes

作　　者：袁华[1] 高硕[1] 曹晨忠[1] 

机构地区：[1]湖南科技大学化学化工学院,湖南湘潭411201

出　　处：《湖南科技大学学报（自然科学版）》2009年第2期84-88,共5页Journal of Hunan University of Science And Technology：Natural Science Edition

基　　金：国家自然科学基金资助项目(20772028);湖南省自然科学基金资助项目(06JJ2002)

摘　　要：将单取代烷烃的性质视为烷基、取代基各自的贡献以及烷基和取代基之间相互作用的贡献之和.用烷基中C-C键和C-H键的键邻接矩阵特征根之和ΣX1CC和ΣX1CH描述烷基的结构特征,以取代基的电负性和单取代甲烷与甲烷之间的热力学性质之差表征取代基对所研究的热力学性质的影响,并用烷基的极化效应指数与取代基电负性的乘积来定量烷基和取代基之间的相互作用.用上述参数对单取代烷烃(RX,X=OH,NH2,NO2,Cl,Br,I,SH,CN等)的气相热容CpΘ、标准摩尔熵SmΘ及标准摩尔生成吉布斯自由能ΔfGΘm建立定量相关模型,交叉验证表明这些模型都具有良好的稳定性和预测能力.The property of monosubstituted alkanes can be regarded as the integration of the constributions of alkyl and substituent together with the interaction between them. The sum of eigenvalues （ ∑XICC、∑XICHH） of bond adjacent matrices of C-C and C-H bonds were employed to characterize the structure of alkyl. The electronegativity of substituent and the difference of thermodynamic property between methane and monosubstituted methane were used to express the influence of substituent on the interested thermodynamic property. In addition, the interaction between alkyl and substituent was quantified by the product of polarizability effect index （PEI） of alkyl and electronegativity of substituent.The quantitative structure-property relationship models against gas heat capacity （Cps ）, standard molar entropy （Sm） and standard molar Gibbs free energy of formation （ Δf Gm ） of monosubstituted alkanes （RX, X=OH, NH2, NO2, C1, Br, I,SH, CN, etc） were consmmted with the above parameters. Cross validations indicate that all these models are of good stability and predictivity. 4tabs., 10refs.

关 键 词：热容 熵 吉布斯自由能 键邻接矩阵特征根 极化效应指数 单取代烷烃 

分 类 号：O647[理学—物理化学]