Hydrogen bonding dynamics of cyclodextrin-water solutions by depolarized light scattering

Depolarized light scattering measurements performed on aqueous solutions of α‐cyclodextrin are used for investigating the hydration properties of this natural cyclic oligosaccharide, which is well known for its ability to form inclusion complexes with a large variety of guest hydrophobic molecules. The spectral analysis allows the characterization of the solvent relaxation process assigned to hydration water, which is found to be seven to eight times slower than the bulk. As a structural information, the number of water molecules involved in the hydration process is also estimated at about 46. These results are a key step for understanding the role played by water in determining the properties of different forms of cyclodextrins and their derivatives, in turn related to complexation ability of these macrocycles. Copyright © 2011 John Wiley & Sons, Ltd. Depolarized light scattering measurements performed on aqueous solutions of cyclodextrins are used to investigate the hydration properties of these natural cyclic oligosaccharides. The analysis of the spectrum allowed to distinguish two different relaxation processes assigned to the continuous formation and breaking of hydrogen bonds between the molecules of free water and those found in the hydration shell of solute.