Bond Orbital-Connection Matrix Method to Predict Refractive Indices of Alkanes

Based on the comprehension of the specific structural features affecting the refractive indices of the compounds, two descriptors PX1CC and PX1CH extracted from the bond orbital-connection matrix (BOCM) method were employed to develop a QSPR model for predicting the refractive indices of alkanes, chloroalkanes and bromoalkanes. The obtained results confirmed the usefulness of the BOCM method. PX1CC and PX1CH re°ect the ability of the electronic cloud of the alkanes to be polarized; such ability is correlated with the refractive indices of substances. Therefore, the physical meaning of the obtained model can be rationally interpreted from the physical point of view. The present descriptors obtained by the BOCM method have the merit of topological indices (i.e. facility and rapid calculation of the descriptors) and the advantage of quantum descriptors (i.e. explicitly physical meaning of the parameters), which lead to an expectation of wide use in QSAR studies.