Quantitative structure–property relationship of Ev‐degree and Ve‐degree based topological indices : physico‐chemical properties of benzene derivatives

Abstract

AbstractA quantitative structure–property relationship study was performed for the prediction of physical properties of 22 benzene derivatives using ev‐degree and ve‐degree topological indices. These topological indices correlate certain physico‐chemical property with the chemical structure (like molecular weight, enthalpy, boiling point and π‐electron energy of β‐unit of benzene derivatives). At first, a simple linear regression model was developed using ve‐degree and ev‐degree topological indices and the certain physical properties of the considered benzene derivatives. It is found that the atom bond connectivity index () possesses the best correlating ability among several topological indices to predict the boiling point, the ve‐degree based Randić index is the best predictor of enthalpy, the ev degree based Randić index is the best predictor of π‐electron energy, the sum connectivity index is the best predictor of molecular weight. Second, multiple linear regressions were used for prediction the physical properties (molecular weight, boiling point, enthalpy and π‐electron energy of β‐unit) on the basis of six predictor such as , , , , , and indices. This multi‐linear regression model shows the 100% variation in π‐electron energy of β‐unit. A Maple software based algorithm is used for the calculations of topological indices and the statistical analysis is performed with the SPSS software. The calculations of the ev and ve degree based topological indices of chemical structure of styrene‐butadiene rubber are presented at the end to illustrate the given Maple algorithm.