QSPR Analysis of Phenylthio Phenylsulfinyl and Phenylsulfonyl Esters

摘要

Quantitative structure-property relationships (QSPR) were developed with the quantum semi-empirical descrptors computed by AM1 Hamiltonian in MOPAC7.0 for phenylthio, phenylsulfinyl and phenylsulfonyl esters. Using stepwise regression analysis with a cross-validation procedcure, the most potent and informative descriptors were screened out from a group of 19 quantum chemical semi-empirical dscriptors, including steric and electronic types, to build QSPR models. Several equations were obtained and used to estimate and predict octanol/water partition coeffcients and reversed phase high-performance liquid chromatography (HPLC) capacity factors for a series of 30 similar sulfur-containing compounds. The results indicate that mo-lecular descriptors, including average mnolecular polarizability (#alpha#), energy of the lowest unoccupied molecular orbital (E_LUMO), net atomic charge on carbon atoms in the carbonyl (Q_CO), molecular weight (M_W), the most positive atomic charge on hydrogen atom (Q_H~+), and net atomic charge on oxygen atoms in the gfroup-NO_2 (Q_NQ2) are the main factors affecting the octanol/water partition coefficients of the compounds under study. And quantum descriptors, covering the most negative atomic charge on an atom (Q~0), net atomic charge on carbon atoms in the carboxy (Q_COO), molecular weight (M_W), heat of formation (H_F), the most positive atomic charge on a hydrogen atom (Q_H~+), and total energy (T_E), are the main factors affecting HPLC capacity factors of these compounds. Rational mechanisms for the two physico-chemical properties of the sulfur-containing carboxylates were discussed and interpreted.