Macromolecules are characterized by their particular arrangement of H bonds. Many of these interactions involve a single donor and acceptor pair, such as the regular H-bonding pattern between carbonyl oxygens and amide H(+)s four residues apart in α-helices. The H-bonding potential of some acceptors, however, leads to the phenomenon of overcoordination between two donors and one acceptor. Herei...

the influence of cation-π interactions on the strength and nature of intramolecular o...h hydrogen bond has been investigated by quantum chemical calculations in orthohydroxy benzaldehyde (hba) compound. ab initio calculations have been performed at mp2/6-311++g** level of theory. vibrational frequencies and physical properties such as chemical potential and chemical hardness of these compounds...

in the present work, dft calculations are employed to obtain the optimized structures of 4-acyl pyrazolone tautomers (19 tautomers) using b3lyp/6-311++g** calculations. inaddition, molecular parameters, ir frequencies and relative energies are extracted for alltautomers. the existence of aromatic ring, keto tautomer (versus enol tautomer), n-h bond(versus c-h bond) and c=n double bond (versus n...

We report detailed studies on the characterization of an intramolecular NH-F hydrogen bond formed within a fluorinated "proton sponge" derivative. An ammonium ion, generated from 8-fluoro-N,N-dimethylnaphthalen-1-amine, serves as a charged hydrogen bond donor to a covalently bound fluorine appropriately positioned on the naphthalene skeleton. Potentiometric titrations of various N,N-dimethylnap...

In the title compound, C(12)H(12)N(2)O(2)S, there are S-H⋯N and N-H⋯O hydrogen-bond inter-actions. The N-H⋯O hydrogen bond is bifurcated, with the hydrogen being simultaneously donated to two equivalent O atoms, forming one intra- and one inter-molecular N-H⋯O bond with an R(1) (2)(4) motif. The motif of the S-H⋯N hydrogen bond is R(2) (2)(12).

The reaction of 2,2'-dithio-bis(benzenamine) with furan-2-carbonyl chloride produced the bis-amide title compound, C(22)H(16)N(2)O(4)S(2), which, in the crystal, formed a helix; the structure consists of two planar furanoylbenzenamines related by an improper rotation of 96.3° about the S-S bond. The N-furanoylbenzenamine units are planar (maximum deviations = 0.316 and 0.132 Å). Each electron-d...

The influence of cation-π interactions on the strength and nature of intramolecular O...H hydrogen bond has been investigated by quantum chemical calculations in orthohydroxy benzaldehyde (HBA) compound. Ab initio calculations have been performed at MP2/6-311++G** level of theory. Vibrational frequencies and physical properties such as chemical potential and chemical hardness of these compounds...

In the crystal of the title salt, 2C(2)H(8)N(+)·C(6)H(4)O(8)S(2) (2-), the anion lies on a center of inversion. The dimethyl-ammonium cation forms one N-H⋯O hydrogen bond and another bifurcated N-H⋯O hydrogen bond. The hy-droxy group links with the sulfonyl group via an inter-molecular O-H⋯O hydrogen bond. These N-H⋯O and O-H⋯O hydrogen bonds generate a three-dimensional network.

The solvothermal synthesis and crystal structure of [bis(thiocyanato-?N)bis(tris(pyridin-2-yl-?N)amine)iron(II)] ( 1 ) are described. obtained was i subjected to theoretical analysis interaction energies intra- intermolecular bonding. This comprehensive study illustrates the richness non-covalent interactions that exhibited by nitrile anionmetal complexes. neutral complex lies on a crystallogra...

In the mol-ecule of the title compound, C(12)H(16)N(2)O(4), an intra-molecular N-H⋯O hydrogen bond results in the formation of a six-membered ring having an envelope conformation. In the crystal structure, a bifurcated intra/intermolecular N-H⋯(O,O) hydrogen bond generates inversion dimers.