Does intramolecular hydrogen bond play a key role in the stereochemistry of alpha- and beta-D-glucose?

Autor(es)

Silla, Josue M. ^[1] ; Cormanich, Rodrigo A. ^[2] ; Rittner, Roberto ^[2] ; Freitas, Matheus P. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Lavras, Dept Chem, BR-37200000 Lavras, MG - Brazil

^[2] Univ Estadual Campinas, Inst Chem, BR-13083970 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Carbohydrate Research; v. 396, p. 9-13, SEP 19 2014.
• Citações Web of Science: 23

Resumo

Four alpha- and three beta-isomers of the D-glucose were optimized in gas phase using ab initio (MP2) and DFT (omega B97X-D) methods, both using the aug-cc-pVDZ basis set. While earlier works suggest that the orientation of the hydroxyl groups is due to intramolecular hydrogen bonds (H-bonds), the present study reveals that most H-bonds forming five-membered rings are either weak or even do not exist. The quantum theory of atoms in molecules (QTAIM) analysis showed only a few cases of H-bond in D-glucose, particularly for those H-bonds forming six-membered rings, while the non-covalent interactions (NCI) analysis indicated that most intramolecular H-bonds are not strong enough to justify the counter-clockwise arrangement of the OH center dot center dot center dot O chains. Natural bond orbital analysis supported the findings obtained from QTAIM and NCI analyses and indicated that the anomeric effect for D-glucose in the gas phase is governed by a balance of steric, electrostatic, and hyperconjugative interactions. (C) 2014 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 11/01170-1 - Estudos físico-químicos de compostos orgânicos: interações de longa distância e análise conformacional de compostos organofluorados
• Beneficiário: Rodrigo Antonio Cormanich
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 12/03933-5 - Equilíbrios conformacionais e interações intramoleculares em uma série de aminoácidos: abordagem teórica e experimental
• Beneficiário: Roberto Rittner Neto
• Modalidade de apoio: Auxílio à Pesquisa - Regular