QSPR models of n-octanol/water partition coefficients and aqueous solubility of halogenated methyl-phenyl ethers by DFT method

The possible molecular geometries of 134 halogenated methyl-phenyl ethers were optimized at B3LYP/6-31G* level with Gaussian 98 program. The calculated structural parameters were taken as theoretical descriptors to establish two new novel QSPR models for predicting aqueous solubility (−lgSw,l) and n-octanol/water partition coefficient (lgKow) of halogenated methyl-phenyl ethers. The two models achieved in this work both contain three variables: energy of the lowest unoccupied molecular orbital (ELUMO), most positive atomic partial charge in molecule (q+), and quadrupole moment (Qyy or Qzz), of which R values are 0.992 and 0.970 respectively, their standard errors of estimate in modeling (SD) are 0.132 and 0.178, respectively. The results of leave-one-out (LOO) cross-validation for training set and validation with external test sets both show that the models obtained exhibited optimum stability and good predictive power. We suggests that two QSPR models derived here can be used to predict Sw,l and Kow accurately for non-tested halogenated methyl-phenyl ethers congeners.

► Molecular geometries of 134 halogenated methyl-phenyl ethers were optimized using DFT method.
► The calculated structural parameters were taken as theoretical descriptors to establish two QSPR models.
► Two established QSPR models exhibit optimum stability and good predictive power.
► The two QSPRs derived can be used to predict accurately Sw,l and Kow for halogenated methyl-phenyl ethers.
► The values of −lgSw,l and lgKow for halogenated methyl-phenyl ethers were compared with those of PCDDs, PCNs and PCBs.