C-13 NMR-STUDY ON DIASTEREOMERIC INTERACTIONS BETWEEN CELLULOSE TRIS(4-METHYLBENZOATE) AND 1-PHENYLETHANOL ENANTIOMERS

For investigating the mechanism of chiral recognition by cellulose der ivatives, C-13 NMR spectra of 1-phenylethanol were measured in CDCl3 i n the presence or absence of cellulose tris(4-methylbenzoate) (1). (R) - and (S)-enantiomers of 1-phenylethanol showed different chemical shi fts in the presence of 1. The degree of chemical shift difference was large at aromatic ipso carbon (1'-C) and methine carbon (1-C) with a h ydroxyl group. Spin-lattice relaxation times (T1s) were also measured to compare mobilities of the enantiomers. In the presence of 1, T1 for each carbon of the (R)-enantiomer was shorter than that for correspon ding carbon of the (S)-enantiomer. The presence of 1 restricts the mob ility of the (R)-enantiomer more than that of the (S)-enantiomer. T1 d ifference between (R)- and (S)-enantiomers was large at 1-C. The resul ts indicate that 1-phenylethanol is chirally recognized by 1 at the po int of 1-C carbon.