QSPRs for the prediction of photodegradation half-life of PCBs in n-hexane†

Abstract

By partial least squares (PLS) regression analysis, a quantitative structure-property relationship (QSPR) model was developed for photodegradation half-life (t 1/2) of polychlorinated biphenyls (PCBs) in n-hexane solution under UV irradiation. Quantum chemical descriptors computed by PM3 Hamiltonian were used as predictor variables. The cross-validated value for the optimal QSPR model was 0.589, indicating good predictive capability for log t 1/2 values of PCBs in n-hexane. The QSPR results show that standard heat of formation (ΔH f), total energy (TE), and molecular weight (Mw ) have dominant effect on t 1/2 values of PCBs in n-hexane. Increasing ΔH f and TE values or decreasing Mw values of the PCBs leads to decrease of log t 1/2 values. In addition, increasing the largest negative atomic charge on a carbon atom and dipole moment of the PCBs leads to decrease of log t 1/2 values. †Presented at CMTPI 2005: Computational Methods in Toxicology and Pharmacology Integrating Internet resources (Shanghai, China, October 29–November 1 2005).