Quantitative structure–property relationships on photodegradation of polybrominated diphenyl ethers

By partial least squares (PLS) regression, quantitative structure–property relationship (QSPR) models were developed for photodegradation rates (kp) and quantum yields (Φ  ) of polybrominated diphenyl ethers (PBDEs) in methanol/water (8:2), and photodegradation rates in pure methanol by UV light in the sunlight region, respectively. Quantum chemical descriptors computed by PM3 Hamiltonian were used as predictor variables. The cross-validated Qcum2 values for three optimal QSPR models of PBDEs are above 0.90 (remarkably higher 0.50), indicating good predictive abilities for log kp and log Φ values of PBDEs. The QSPR results show that log kp values of PBDEs in methanol/water (8:2) and in pure methanol are governed by different molecular structural descriptors, respectively, which implies that photodegradation rates of PBDEs are affected by the characteristics of solution in which it takes place.