title: Vibrational coupling as diagnostic for intramolecular hydrogen bonds of carbohydrates in aqueous solution.
abstract: The coupling of nuC-O and deltaO-D vibrations in the 1200-900 cm(-1) IR range leads to band shifting in opposite directions, which provides information on intramolecular hydrogen bonding of carbohydrates in aqueous solution. The aqueous solution IR spectra of 2-acetamide-1,6-anhydro-2-deoxy-D-glucopyranose and cis-1,2-cyclopentanediol and tetrahydrofuran-ethanol mixtures are reported. Frequency upshifting upon deuteration is observed for the nuC-O bands of both a hydrogen bond acceptor and donor in ether-hydroxyl and hydroxyl-hydroxyl contacts. The 1200-900 cm(-1) range can be used to reveal the presence of intramolecular hydrogen bonds in aqueous carbohydrates, unlike the OH stretching region, which cannot be used in this sense due to carbohydrate band masking by the strong nuOH IR absorption of water.
authors.affiliation: Instituto de Estructura de la Materia (CSIC), Serrano 121, 28006 Madrid, Spain. p.carmona@iem.cfmac.csic.es
authors.forename: Pedro
authors.initials: P
authors.lastname: Carmona
authors.forename: M
authors.initials: M
authors.lastname: Molina
authors.forename: N
authors.initials: N
authors.lastname: Aboitiz
authors.forename: C
authors.initials: C
authors.lastname: Vicent
mesh_terms: D002236:Carbohydrate Conformation; D002241:Carbohydrates / Q000737:chemistry*; D000431:Ethanol / Q000737:chemistry; D005663:Furans / Q000737:chemistry; D006860:Hydrogen Bonding; D013055:Spectrophotometry, Infrared; D014732:Vibration; D014867:Water / Q000737:chemistry*
chemical_list: D002241:Carbohydrates; D005663:Furans; D014867:Water; D000431:Ethanol; C018674:tetrahydrofuran