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An Investigation of Chiral Recognition in Electrokinetic Chromatography by means of NMR Spectroscopy Kevin Morris, Department of Chemistry, Carthage College.
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An Investigation of Chiral Recognition in Electrokinetic Chromatography by means of NMR Spectroscopy Kevin Morris, Department of Chemistry, Carthage College The NMR relaxation rate ratio method was used to investigate the binding of the chiral compound 1,1'-binaphthyl-2,2'-diyl hydrogen phosphate (BNP) to molecular micelles with different dipeptide headgroups. Spin-lattice and spin-spin relaxation times were measured for each BNP proton and used to calculate each proton’s correlation time or the time required for the proton to move through one radian. These experiments showed that in the presence of molecular micelles that gave low chiral selectivity, a, all BNP protons had the same correlation time and thus the BNP molecule moved in an isotropic fashion.1 On the other hand, in experiments with the molecular micelles that gave high chiral resolution selectivity, the BNP protons had different correlation times. This result showed that in the presences of these molecular micelles the BNP molecule moved in an anisotropic fashion caused by different portions of the molecule experiencing different interactions with the polymer. Thus, the motional anisotropy of bound chiral molecules was found to be an effective probe of chiral recognition. high chiral selectivity anIsotropic motion correlation time range (ns) low chiral selectivity Isotropic motion chiral selectivity, a 1.Billiot, F.H.; Billiot, E.J; Warner, I.M. J. Chromatogr. A, 2001, 922, 329.