Characterization of some GLC chiral stationary phases: LFER analysis

Linear free energy relationships (LFERs) have been used to characterize 19 chiral stationary phases (CSPs) using retention data of Berthold et al, (Anal, Chem, 1995, 67, 849-857); of the 19 chiral phases, 17 were cyclodextrin derivatives, Most of the CSPs had moderate-to-large dipolarity/polarizability and considerable hydrogen bond basicity, Of the 19 CSPs, 17 had no hydrogen bond acidity at all, and 2 had only limited hydrogen bond acidity, so that no connection between enantioselective resolution and CSP hydrogen bond acidity could be made, However, there is little or no connection between enantioselective resolution and dipolarity/polarizability or hydrogen bond basicity of the CSPs, even though retention indexes themselves were well correlated through LFERs that contained hydrogen bond and dipolarity/polarizability descriptors. It is suggested that enantioselective resolution of compounds with basic groups attached to the stereogenic center may possibly be enhanced through the use of CSPs that possess considerable hydrogen bond acidity.