An information topological index based on Randic M.molecular connectivity index was constructed and calculated for 58 alkyl cycloalkanes. The information topological index, Randic connectivity index and number of carbon atoms were correlated with 11 kinds of thermodynamic and physico-chemical properties such as gaseous standard formation heat, gaseous standard entropy, gaseous standard formation free energy, boiling point, critical temperature, critical pressure, critical volume, evaporation heat, density, capacity and surface tension of the alkyl cycloalkanes. A general equation for calculating the physico-chemical properties was proposed. The empirical equations for the different physico-chemical properties were worked out through regression on computer. The correlation coefficients of the regressions were high (most of them were greater than 0.99). The calculated results and analysis of the deviations indicated that the topological indices were correlated with the thermodynamic and physico-chemical properties very well. The empirical equations were acceptable for estimating the physico-chemical properties of alkyl cycloalkanes.

Key words: alkyl cycloalkane, information topological index, physico-chemical property, empirical equation