Acoustical Spectroscopy of Carbohydrate Aqueous Solutions: Saccharides; Alkyl Glycosides; Cyclodextrins. Part I. Conformer Variations

Acoustical attenuation spectra in the frequency range 12 kHz – 2 GHz and nonequilibrium time domain measurements are briefly reviewed for aqueous solutions of various mono- and disaccharides as well as alkyl glycosides. Several relaxation regimes emerge with relaxation times between 10^-11 s and 10^3 s. In this paper relaxation terms reflecting conformational changes are discussed, particularly mutarotation (10^3 s), chair-chair ring inversion (1 ąs), two modes of pseudorotation (100 ns, 10 ns), disaccharide ring isomerisation (10 ns), and exocyclic side group rotation (1 ns).