title: Vibrational analysis of N-acetyl-alpha-D-glucosamine and beta-D-glucuronic acid.
abstract: Infrared spectra of solid and aqueous solutions of N-acetyl-alpha-D-glucosamine and beta-D-glucuronic acid have been investigated by means of Fourier transform infrared (FT-IR) spectroscopy and quantum chemical density functional theory (DFT) calculations. The errors of the computed harmonic force field were corrected according to the scaled quantum mechanical (SQM) method of Pulay, with scale factors partly from the literature and partly developed here. Scale factors for the hydrogen-bonded OH groups were determined by SQM treatment of ethylene glycol. The IR spectra and test computations revealed that beta-D-glucuronic acid is present as a dimer, formed by hydrogen-bonding between the COOH groups, in the solid phase. On the basis of the calculated results, 64 and 56 bands in the 4000-50 cm(-1) range of the FT-IR spectra have been assigned for N-acetyl-alpha-D-glucosamine and beta-D-glucuronic acid, respectively.
authors.affiliation: Research Group for Materials Structure and Modeling of the Hungarian Academy of Sciences, Budapest University of Technology and Economics, H-1111 Budapest, Szt. Gellért tér 4, Hungary. akovacs@mail.bme.hu
authors.forename: Attila
authors.initials: A
authors.lastname: Kovács
authors.forename: Balázs
authors.initials: B
authors.lastname: Nyerges
authors.forename: Vladislav
authors.initials: V
authors.lastname: Izvekov
mesh_terms: D000117:Acetylglucosamine / Q000737:chemistry*; D020723:Glucuronic Acid / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D013055:Spectrophotometry, Infrared; D014732:Vibration
chemical_list: D020723:Glucuronic Acid; D000117:Acetylglucosamine