Homopolypeptide‐based alignment media can induce different orientations of enantiomers as a result of their α‐helical structures. This property enables the discrimination of enantiomers through anisotropic NMR parameters such as residual dipolar couplings (RDCs). In this paper, the enantiodiscriminating properties of two alignment media derived from polyglutamic acid derivatives – poly‐γ‐benzyl‐L‐glutamate (PBLG) and poly‐γ‐ethyl‐L‐glutamate (PELG) – are compared and discussed. The two analytes, isopinocampheol and β‐pinene, are investigated, and the role of the lateral side chain of the homopolypeptide in the orientation process is examined.

Lyotropic liquid crystalline (LLC) phases of polyglutamic acid derivatives, such as poly-γ-benzyl-l-glutamate, are suitable alignment media for organic structure elucidation by NMR spectroscopy. Their helical structure is responsible for enantiodiscrimination. As part of our ongoing investigations concerning the alignment mechanism(s) of these systems, we considered whether an additional chiral center in the side chain could improve enantiodiscrimination relative to the helical polymer with an achiral side chain. Therefore, the diastereoisomers poly-γ-S-2-methylbutyl-l-glutamate (PSMBLG) and poly-γ-S-2-methylbutyl-d-glutamate (PSMBDG) were synthesized. These two polymers were tested for their liquid crystallinity and suitability as alignment media. The spatial structure of the solutes (-)-curcumol and isopinocampheol (IPC) were validated by the residual dipolar coupling data obtained. Additionally, enantiodiscrimination of IPC was observed in the new alignment media and compared with the enantiodiscrimination of IPC in other homopolypeptides.