DFT-M062X quantum chemical computations on the Ala3H(+)·nH2O (n up to 37) complexes have been performed to model for hydration effects on the molecular properties of protonated trialanine. Following simple rules to arrange water molecules around the peptide, geometry optimization allows us to find four minima corresponding to the unfolded extended (β) and polyproline II (PPII) conformations. Th...

Neutron diffraction provides an experimental method of directly locating H atoms in proteins, a technique complementary to ultra-high-resolution X-ray diffraction. Three different types of neutron diffractometers for biological macromolecules have been constructed in Japan, France and the USA, and they have been used to determine the crystal structures of proteins up to resolution limits of 1.5...

Hydrated polysaccharides are major constituents of cartilage and play an important role in its water-binding properties. Infrared (IR) spectroscopy and sorption isotherms have been used to investigate the hydration behavior of the glycosaminoglycans hyaluronic acid and chondroitin sulfate. IR-dichroism of the vibrational modes of the pyranose ring is found at relative humidities (RH) smaller th...

In the title compound, C(17)H(20)FN(3)O(3)·6H(2)O, the pefloxacin (pef) neutral zwitterion is accompanied by six water mol-ecules of hydration. An extensive network of O-H⋯O and N-H⋯O hydrogen bonds help to establish the crystal packing.

In the title compound, C18H13N3O2·H2O, the oxa-diazole ring forms dihedral angles 7.21 (10) and 21.25 (11)° with the quinoline and benzene rings, respectively. The crystal structure features O-H⋯N hydrogen bonds and is further consolidated by C-H⋯O hydrogen-bonding inter-actions involving the water molecule of hydration.

Square water takes into account the directionality of hydrogen bonds. The model is reviewed and its properties as a solvent for apolar particles are studied through Monte Carlo simulations. Specific heat measurements are used to identify phase separation. Data for comparison with the lattice gas on the square lattice are presented and the relation to non-associating solvents is discussed. Data ...

The six-vertex lattice model is augmented with ionic vertices and bonding defects. These represent sources and sinks for hydrogen atoms, and the extra vertices account for the pH of water. This 14-vertex lattice model with Bjerrum bond defects represents a not unrealistic model of ice, and possibly also of structured water next to a surface. Such surfaces polarise the adjacent molecules, which ...

Dynamical properties of F –water and Cl –water hydrogen bonds in aqueous solution have been studied by ab initio QM/MM molecular dynamics simulations, in which the whole first hydration sphere of the anion was treated at Hartree–Fock level using respe ies as lvat D95V+, 6-31+G and D95V++ basis sets for F , Cl and water, and shifts in the corresponding bending and stretching frequenc ing the ion...

Dimethyldodecylamine-N-oxide (DDAO) has only one polar atom that is able to interact with water. Still, this surfactant shows very hydrophilic properties: in mixtures with water, it forms normal liquid crystalline phases and micelles. Moreover, there is data in the literature indicating that the hydration of this surfactant is driven by enthalpy while other studies show that hydration of surfac...