NMR Spectra of Glycine Isotopomers in Anisotropic Media: Subtle Chiral Interactions

Abstract

NMR spectra of deuterated glycine-2-¹³C revealed interactions between chiral anisotropic gelatin and κ-carrageenan gels and the prochiral and chiral isotopomers. The ¹H, ²H and ¹³C NMR spectra of mixtures of racemic mono- and prochiral bis-deuterated glycine-2-¹³C were resolved and well simulated using distinct dipolar coupling constants <i>D</i>_CαH and <i>D</i>_CαD for the enantiomers and also for the -¹³C_αD₂- group (<i>D</i>_C,DA, and <i>D</i>_C,DB). The orientation of the proton or deuteron on the ¹³C_α-atom of glycine was assigned by analogy with alanine and lactate assuming that the molecular orientation of glycine isotopomers is the same. The assignment of the prochiral sites was derived from chiral analogues