QSPR modeling of the logK ow and logK oc of polymethoxylated, polyhydroxylated diphenyl ethers and methoxylated-, hydroxylated-polychlorinated diphenyl ethers.

In the present study, the structural parameters of 209 types of polymethoxylated diphenyl ethers (PMeODEs), 209 types of polyhydroxylated diphenyl ethers (PHODEs), seven types of methoxylated-polychlorinated diphenyl ethers (MeO-PCDEs) and seven types of hydroxylated-polychlorinated diphenyl ethers (HO-PCDEs) were calculated using the Gaussian 09 program at the B3LYP/6-311G** level. Using structural and positional parameters as descriptors, quantitative structure-property relationships (QSPR) models for the prediction of n-octanol/water partition coefficient (logKow ) and soil sorption coefficient normalized to organic carbon (logKoc ) were established and verified. The position parameters N2(6) , N3(5) and N4 were the main positional factors influencing logKow and logKoc of PMeODEs and PHODEs. The molecular polarizability α was entered into the QSPR models of the logKow and logKoc of PMeODEs, PHODEs and MeO/HO-PCDEs, indicating that the molecular volume could influence the two environment-related properties of DEs significantly. All of the established QSPR models showed good goodness-of-fit, robustness, and predictive ability. The two models for all of the tested DEs are slightly inferior compared with the models for only a class of compounds. In addition, application domain analysis indicated that the models reliably predicted the logKow and logKoc of the mon- to hexa-DEs.