The present paper focuses on the connection amongst the structure of 25 liquid crystals in the benzylideneaniline class and some of their physico-chemical properties. Simple and multiple correlations between transition temperatures and 34 calculated molecular descriptors (25 topological indices and 12 Van der Waals parameters), for each compound, were made. Simple and multiple correlations amongst topological indices and Van der Waals parameters, respectively, observing the variations taking place, are presented.

The octane number (ON, MON and PON) for the molecular structures of 18 octane isomers have been correlated using the quantitative structureproperty relationship (QSPR) method, with topological index SD. For single parameter correlation the index SD shows poor results (RON, r = 0.406; MON, r = 0.490; PON, r = 0.448), whereas for two-parameter correlation almost any combination among the above DC was found to give relatively high r value. The best correlation coefficients are as follows: for RON, r = 0.993; MON, r = 0.968; PON, r = 0.985. For RON, the best model obtained by our regression analysis is RON = −227.218 + 7.63 ∗ SD − 37.111 ∗ DC , with r = 0.993, s = 4.8, F = 534