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Updated: Jun 3, 2025

Author Spotlight: Unveiling the Structural and Dynamic Aspects of Glycan Molecular Recognition
Published on: May 17, 2024
Analysis of the NMR Parameters Shielding and Spin-Spin Coupling Constants of Glycine Conformers
Danillo Valverde1,2, Herbert C Georg3, Gabriel I Pagola4
1Laboratory for Chemistry of Novel Materials, University of Mons, Place du Parc, 20, 7000 Mons, Belgium.
Abstract:
In this study, we worked at the CCSD/aug-cc-pVTZ level to obtain the conformers of glycine in its neutral and zwitterionic forms in the gas and water phases. We then computed the NMR properties (spin-spin coupling constants and nuclear magnetic shieldings) at the SOPPA/aug-cc-pVTZ-J level. We attempt to elucidate the apparent discrepancy arising from two previous works by Valverde et al. [J. Chem. Phys., 2018, 148, 024305] and Caputo and Provasi [Sci, 2021, 3, 41]. Our optimized structures align with previous theoretical predictions, although some geometries were not found. Additionally, our results suggest that in the gas phase the Δ 1J(O,C) = 1J(Ocis,CO) - 1J(Otrans,CO) is positive when the acid group is in the trans conformation and negative in the cis conformation; however, this trend is not well reproduced in water. From magnetic shielding calculations, we cannot distinguish between an O-H in the cis or trans conformation.
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