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.