Investigation of the enantioselective separations of alpha-alkylarylcarboxylic acids on an amylose tris(3,5-dimethylphenylcarbamate) chiral stationary phase using quantitative structure-enantioselective retention relationships - Identification of a conformationally driven chiral recognition mechanism

A series of 28 chiral alpha-alkyl arylcarboxylic acids were chromatographed on an amylose tris(3,5-dimethylphenylcarbamate) chiral stationary phase (AD-CSP). The retention data were correlated to a series of molecular descriptors to produce quantitative structure-enantioselective retention relationships (QSERR) incorporating the hydrogen bonding ability and aromaticity of the solutes. The QSERR equations were used to guide molecular modelling experiments designed to investigate the chiral recognition mechanism responsible for the observed enantioselective separations. The results of the study indicate that unlike the standard ''three-point interaction'' model of chiral recognition, enantioselectivity was due to a ''conformationally driven'' chiral recognition process.