Study on Structure-Refractive Index Relationship of Cycloalkanes and Alkanes

A new structure information autocorrelation topological index tX is designed and developed based on the vertex degree of molecular topology and autocorrelation function of mathematics. Quantitative structureproperty the relationships for estimating the refractive index of cycloalkane and alkane are set up based on multiple linear regression. The vertex degree is defined as βi .The structure information autocorrelation topological index tX is set up with the βi. The refractive index （nD）， for the 64 cycloalkanes, are correlated with this topological indices. The index， for the 27 alkanes, are also correlated with this topological indices. The calculated results showed that the calculated refractive index of cycloalkanes and alkanes are in good agreement with the experimental data， with the mean velative deviation 0.25%. With the established model， the refractive index of the other 5 alkanes are predicted.