A comparison of semiempirical and first principle methods for establishing toxicological QSARs of nitroaromatics

Semiempirical MO AM1 and PM3, ab initio MO HF and density functional theory (DFT) B3LYP methods were used to calculate the electronic and structural properties of 28 nitroaromatics. QSARs were established based on these properties and the toxicity of nitroaromatics to the fathead minnow. The results showed that the models established based on the first principle methods (HF and DFT-B3LYP) are better than that based on semiempirical methods (AM1 and PM3). HF model is a little better than DFT-B3LYP model on correlation and significance. But the B3LYP model gives more reasonable interpretation of nitroaromatics toxic mechanism. Based on the model, the toxic mechanism of the nitroaromatics was discussed.