OH...O bond in liquidfs spectroscopyhydrogen bondingA non-empirical theory is presented showing how infrared pump–probe spectroscopy can be used to measure subpicosecond variations of the oxygen–oxygen distribution functions in liquid water, Δg(r, τ). It should be emphasised that the equations...
Here, ΔH is the change in bond energy, or bond enthalpy and ∑H is the sum of the bond energies for each side of the equation. The O-H bond in water is a covalent bond with a higher bond energy than the hydrogen bond. The bond energy of the covalent O-H bonds in water (...
In Table 2, the parameters obtained from the analysis of ectoine solu- tions are compared to average parameters for an instantaneous H-bond configuration in liquid water calculated by Modig et al.49. Intra-molecular contributions from OD (0.98 Å) and DD (1.51 Å) bonds with a ...
breakage) is 1.4±0.1 cm3/mol H-bond, which corresponds to the volume difference between a large dispersion maximum at 2675 cm1(near the OD stretch ω of HDO in dense supercritical water) and a large, broad minimum centered near 2375 cm1(just below the OD stretch ω of HDO in lda ice)...
The role of invariant water molecules in the activity of plant cysteine protease is ubiquitous in nature. On analysing the 11 different Protein DataBank (PDB) structures of plant thiol proteases, the two invariant water molecules W1 and W2 (W220 and W222 in the template 1PPN structure) were ...
The infrared spectra of water dimers formed from H2O, D2O, and HDO in krypton matrices have been recorded. Thermal equilibria between Hand D‐bonded dimers have been studied. D bonding is preferred, and H‐bonded dimers are approximately 60 cm1 less stable than D‐bonded dimers. The energy di...
In this work the results obtained by means of ultrasonic, viscosity and Raman measurements on trehalose—water solutions, are presented. The ultrasonic data show that the mixing process is not ideal and that the water—trehalose interaction strength, because of the saturation of H-bond sites, decr...
Intra- and intermolecular H-bond mediated tautomerization and dimerization of 3-methyl-1,2-cyclopentanedione: Infrared spectroscopy in argon matrix and CCl... Mid-infrared spectra of 3-methyl-1,2-cyclopentanedione (3-MeCPD) have been recorded by isolating the molecule in a cold argon matrix (8...
When the reaction was carried out in the absence of norbornene, a significant amount of H/D exchange was also observed, but again only at the ortho-position (Fig. 5b). The proton source of the H/D exchange appears to be an NH bond. This H/D exchange between the ortho-C–H bond ...
limitingQstructuresoccurringinthestructuraldiffusionprocess:initially,thedefectislocalizedasanH9O4+structure,composedofanH3O+corethatdonatesthreeHbondstoneighboringwatermolecules;subsequently,duetothermalfluctuationsinthesecondshell,theprotonmigratesalonganHbondandbecomesequallysharedbetweentwowatermolecules,substantiallyforming...