Premium
Molecular Dynamics and Conformational Kinetics of Mono‐ and Disaccharides in Aqueous Solution
Author(s) -
Behrends Ralph,
Kaatze Udo
Publication year - 2005
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.200400508
Subject(s) - mutarotation , chemistry , pseudorotation , disaccharide , relaxation (psychology) , aqueous solution , carbohydrate chemistry , dielectric , kinetics , carbohydrate , computational chemistry , ring flip , spectral line , molecule , crystallography , stereochemistry , ring (chemistry) , organic chemistry , psychology , social psychology , physics , optoelectronics , quantum mechanics , astronomy
Acoustical attenuation spectra between 10 kHz and 2 GHz, complex dielectric spectra between 300 kHz and 40 GHz, and time‐resolved non‐equilibrium measurements are reported for aqueous solutions of various mono‐ and disaccharides with and without 2:1 valent salts. The spectra reveal a variety of relaxation regimes with relaxation times between 1 μs and 10 ps. In addition, the time‐resolved observations enable the study of the mutarotation with relaxation times on the order of 10 3 s. Variation of the concentration and temperature as well as a careful choice of the saccharides allow a discussion of the relaxation processes in terms of a chair–chair ring inversion, two modes of pseudorotation, an exocyclic hydroxymethyl group rotation, a carbohydrate–carbohydrate association, and, in the disaccharide solutions, a rotation of the rings relative to another. Salt‐containing solutions show also relaxation phenomena reflecting different steps cation–carbohydrate association and variations in the carbohydrate conformational isomerizations and associations due to interactions with cations.