Development of a QSPR model for predicting octane number of alkanes using SD topological index

The octane number (ON, MON and PON) for the molecular structures of 18 octane isomers have been correlated using the quantitative structure-property relationship (QSPR) method, with topological index . For single parameter correlation the index shows poor results (RON, ; MON, ; PON, ), whereas for two-parameter correlation almost any combination among the above was found to give relatively high value. The best correlation coefficients are as follows: for RON, ; MON, ; PON, .
For RON, the best model obtained by our regression analysis is