Relationship between Connectivity Index and Thermodynamic Property of Alkane

A novel connectivity index mX based on the adjacency matrix was derived in this paper. The index was very easy to calculate and also had good discrimination between isomeric alkanes. Properties, such as the standard enthalpies of formation,the standard entropies,the standard free energies of formation and the boiling point of 85 alkanes are correlated with mX ,with most of the correlation coefficients being over 0 99.The results demonstrate that the property of compounds can be described by the molecular connectivity index mX .