Development of semi-empirical electrotopological index using the atomic charge in QSPR/QSRR models for alcohols
The semi-empirical electrotopological index (I(SET)) used for quantitative structure-retention relationship (QSRR) models firstly developed for alkanes and alkenes, was remodeled for different organic compounds such as ketones, aldehydes and esters. In this study, the I(SET) was developed and optimized to describe the chromatographic retention of aliphatic alcohols on six different stationary phases (5E-30, OV-3, OV-7, OV-11, OV-17 and OV-25). The presence of a hydroxyl group leads to a charge redistribution increasing the interactions between these molecules and the stationary phases relative to the interactions between hydrocarbons and the same stationary phases. These considerations were included in the calculation of I(SET). The simple linear regressions (SLR) between retention indices and the I(SET) for each stationary phase showed good statistical quality, high internal stability and good predictive ability for external groups, especially for stationary phases with low polarity. A single combined model, in which the McReynolds polarity term was added as a descriptor, was developed for all the data points for the stationary phases and the results were of satisfactory predictive quality. The efficiency and the applicability of the approach were demonstrated through the high quality quantitative structure-property relationship (QSPR) model for the boiling point (BP). For this physical property 134 compounds were used; most of them were not included in the original data set employed to develop the I(SET). Copyright (C) 2010 John Wiley & Sons, Ltd.
semi-empirical electrotopological index qspr alcohols gas chromatographic retention indices