Conformation control through concurrent N–H⋯S and N–H⋯O=C hydrogen bonding and hyperconjugation effects - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Chemical Science Année : 2020

Conformation control through concurrent N–H⋯S and N–H⋯O=C hydrogen bonding and hyperconjugation effects

Résumé

In addition to the classical N-H/O]C non-covalent interaction, less conventional types of hydrogen bonding, such as N-H/S, may play a key role in determining the molecular structure. In this work, using theoretical calculations in combination with spectroscopic analysis in both gas phase and solution phase, we demonstrate that both these H-bonding modes exist simultaneously in low-energy conformers of capped derivatives of Attc, a thietane a-amino acid. 6-Membered ring inter-residue N-H/S interactions (C6 g), assisted by hyperconjugation between the thietane ring and the backbone, combine with 5-membered ring intra-residue backbone N-H/O]C interactions (C5) to provide a C5-C6 g feature that stabilizes a planar geometry in the monomer unit. Two contiguous C5-C6 g features in the planar dimer implicate an unprecedented three-centre H-bond of the type C]O/H(N)/SR 2 , while the trimer adopts two C5-C6 g features separated by a Ramachandran a-type backbone configuration. These low-energy conformers are fully characterized in the gas phase and support is presented for their existence in solution state.
Fichier principal
Vignette du fichier
ChemSci_MichelMons.pdf (906.38 Ko) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...

Dates et versions

hal-02917912 , version 1 (20-08-2020)

Identifiants

Citer

Zeynab Imani, Venkateswara Rao Mundlapati, Gildas Goldsztejn, Valerie Brenner, Eric Gloaguen, et al.. Conformation control through concurrent N–H⋯S and N–H⋯O=C hydrogen bonding and hyperconjugation effects. Chemical Science, 2020, 11, pp.9191-9197. ⟨10.1039/D0SC03339A⟩. ⟨hal-02917912⟩
167 Consultations
75 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More