Use of the PI index in predicting toxicity of nitrobenzene derivatives.

The PI Index is a Szeged-like topological index developed very recently. It has useful applications in chemistry which are yet to be investigated thoroughly. Herein, we report quantitative structure-toxicity relationship (QSTR) study using the PI Index. We have used 41 monosubstituted nitrobenzene for this purpose. The results have shown that the PI Index alone is not an appropriate index for modelling toxicity of nitrobenzene derivatives. Combinations of the PI Index with other distance-based topological indices resulted into statistically significant models and excellent results are obtained in pentaparametric models. The predictive potential of the models is discussed on the basis of cross-validation method, as well as by estimating root-mean-square error (RMS).