iceintermolecular mechanicspolymorphismpotential energy functionsthermal expansionwater/ hydrogen bondswater moleculesthermal expansivityThe free energy components of two low pressure crystalline ices and an amorphous form of water are calculated over a wide range of temperatures. The Gibbs free energy at a...
I have an issue with understanding how the hydrogen bonds work in water. We have been taught that the water molecule in its liquid form is (always!) surrounded by 4 other water molecules (through hydrogen bonds), and that in its solid form it is surrounded by 3 water molecules. I've f...
because the ice that forms on ponds and lakes in cold areas of the world acts as an insulating barrier that protects the aquatic life below. If ice were denser than liquid water, ice forming on a pond would sink, thereby exposing more water to the cold temperature. Thus, the pond would...
For a specimen of other usual materials, one bond represents all on average; therefore the thermal response is the same for all the bonds, without any discrimination among all bonds in cooling contraction and thermal expansion36. For water ice, however, the representative O:H-O bond is ...
Liquid water, a system intensively studied in the search for a rationale for its unique properties and many unsolved anomalies1, has been long unanimously believed to have a dominating structure with a symmetric "ice-like" tetrahedral coordination assured by the two-donor and two-acceptor bonding ...
The intermolecular distance is taken as 2.76 A, the intermolecular distance in ice. The effects of both the dipole and quadru- pole moment are taken account of. 0 = OXYGEN = HYDROGEN FIG. I. The hydrogen-bonded water molecules. The left-hand molecule is in the plane of the paper. The...
in water. It is a weak acid, but will dissolve most silicates and hence can be used to etch glass. As the interatomic distance in HF is relatively small, the H–F bond energy is very high and hydrogen fluoride is not a good proton donor. It does, however, form hydrogen bonds. ...
In contrast to HP, MP undergoes only an 8 ps timescale process, which was attributed to interactions between solute and solvent. We concluded that this difference arises from intramolecular hydrogen bonds (IMHBs), which induce drastic structural alterntion upon excitation. Compounds that undergo ...
AuNPs (average diameter is ~15 nm) were used as the plasmonic nanostructures because of their high chemical stability and LSPR in the visible spectrum12. CoTPyP molecules, a variant of metalloporphyrin, were used in this work since the pyridine groups can form strong coordination bonds with ...
proteins:Hydrogen bondsresult in protein folding, which helps the molecule maintain stability and assume a functional configuration. polymers:Polymers that contain carbonyl or amide groups can form hydrogen bonds. Examples include urea and polyurethane and the natural polymer cellulose. Hydrogen bonding in...