QSPR studies on the physicochemical properties of polybrominated diphenyl ethers using theoretical descriptors derived from electrostatic potentials on molecular surface

Geometrical optimization and electrostatic potential calculations were performed at the HF/6-31G* level for all 209 polybrominated diphenyl ethers (PBDEs), which are a group of persistent organic pollutants. Linear relationships between gas-chromatographic relative retention time (RRT), n-octanol/air partition coefficient (lgK_OA) and 298 K supercooled liquid vapour pressures (lg p_L) of PBDEs and theoretical descriptors of molecular structure were established by multiple regression method. The result shows that the parameters derived from electrostatic potential, together with the number of the bromine atoms on the two phenyl rings, can be preferably used to express the quantitative structure-property relationships of PBDEs. The leave-one-out cross-validate coefficients (R_CV) are 0.9819, 0.9911 and 0.9963, and standard deviations (SD) are 0.0424, 0.1384 and 0.1020, respectively, for these three models. This reveals that all these models have high predictive capabilities. The molecular electrostatic potentials are proved to have the general applicability in QSPR model of PBDE congeners.