链烷烃标准熵的拓扑研究

根据核磁共振的峰数及Randic的碳原子支化度,提出了碳原子特征值.基于连接矩阵和碳原子特征值,建立新的连接指数 mY.其中的0阶连接性指数 0Y很容易计算,且对烷烃异构体有很强的区分能力.将157种气态链烷烃的标准熵与其 0Y相关联, R=0.9985, 属于优级模型.与Randic指数的 0χ及倪才华等提出的信息拓扑指数Ix、 IW比较, 0Y具有良好的性质相关性与结构选择性.

Topological Research of Standard Entroplies of Alkanes

According to the peak numbers of the nuclearmagnetic resonance and the Randic embranchment degree of the carbon atom, the carbon atom′s characteristic value is derived. A novel connectivity indexesm Y based on the adjacency matrix and the characteristic worth of the carbon atom is constructed. The zeroth-order connectivity indexes0Yamong the connectivity indexm Y are very easyto be calculated and have good discrimination between isomeric alkanes. The zeroth-order connectivity indexes0Yof 157 alkanes are calculated and correlated with the standard entropies of the alkanes, and the property iswell modeled (R=0.9985). It is concluded that the index0Ybearsgood structure selectivity and property relativity compared with Randic′s0χ and Ni Caihua′s topological information index which provids a valid method for predicting the standard entropies of alkanes.