DFT Study on Nitroaromatics Toxicity to Salmonella typhimurium

The DFT-B3LYP method,with the basis set 6-311G,was employed to calculate the molecular geometries and electronic structures of 20 nitroaromatics. EHOMO,ELUMO,ΔE,ET,QNO2,QC-NO2,μ and V were selected as structural descriptors. The mutagenic toxicity (lg NR) of these compounds to Salmonella typhimurium along with the above eight structural parameters was used to establish the quantitative structure-activity relationships (QSAR) by multiple linear regression. The R2 for the model established in this study was 0.916. The values calculated by the model were in good agreement with the experiment values. The results indicate that the type of substituent affects the toxicity of nitroaromatics directly. A nitro group substitution increases the toxicity of the compounds,while on the contrary,an amino group substitution decreases their toxicity.