Density functional theory has been used to perform a comparative theoretical study of the adsorption and dissociation of H(2)O monomers and icelike bilayers on Ru[0001]. H(2)O monomers bind preferentially at atop sites with an adsorption energy of approximately 0.4 eV/H(2)O. The main bonding interaction is through the H(2)O 1b(1) molecular orbital which mixes with Ru d(z)2 states. The lower-lyi...

In biomolecules, bifurcated H-bonds typically involve the interaction of two donor protons with the two lone pairs of oxygen. Here, we present direct NMR evidence for a bifurcated H-bonding arrangement involving nitrogen as the acceptor atom. Specifically, the H-bond network comprises the Nδ1 atom of histidine and both the backbone N-H and side-chain Oγ-H of threonine within the conserved TXXH ...

The title hydrate, C(10)H(10)N(4)·H(2)O, shows a small twist in the hydro-zone derivative, the dihedral angle between the pyridine and pyrrole rings being 11.08 (12)°. The pyridine and pyrrole N atoms lie to the same side of the mol-ecule being sustained in place by hydrogen-bonding inter-actions with the water mol-ecule. Further inter-molecular O-H⋯N and N-H⋯O hydrogen bonding leads to the for...

The title mol-ecule, C(9)H(8)N(2)O(2), is essentially planar. The crystal structure is stabilized by hydrogen bonding. An intra-molecular N-H⋯O hydrogen bond results in a six-membered ring. Each mol-ecule inter-acts with two others through N-H⋯O and C-H⋯O hydrogen bonding, resulting in the formation of nine-membered rings. These hydrogen bonds generate a two-dimensional polymeric network. There...

In the mol-ecule of the title compound, [Ni(C(5)H(4)NO(3)S)(2)(H(2)O)(4)], the Ni(II) cation is located on an inversion center and is coordinated by four water mol-ecules and two pyridine-3-sulfonate anions with an NiN(2)O(4) distorted octa-hedral geometry. The face-to-face separation of 3.561 (5) Å between parallel pyridine rings indicates the existence of weak π-π stacking between the pyridin...

The mol-ecule of the title compound, C(24)H(18)O(10), a previously unknown coumarin derivative, contains methoxy-carbonyl, 2-butenedioate and benzoyl groups aligned at angles of 28.04 (2), 76.89 (3) and 42.48 (13)°, respectively, to the plane of the coumarin ring system. Intra-molecular O-H⋯O hydrogen bonding between hydr-oxy and carbonyl groups and weak inter-molecular C-H⋯O hydrogen bonding i...

We have synthesized a series of molecules wherein very close C-F---H-C σ-bond interactions, which we have termed "jousting", can be perturbed through both red- and blue-shifted hydrogen bonding effects. These interactions were induced by the placement of various functional groups geminal to the H-C bond. "Jousting" interactions appear to be an admixture of F---H hydrogen bonding and C-H bond co...

In the title mononuclear complex, [Ni(C(9)H(4)N(2)O(4))(H(2)O)(5)]·5H(2)O, the Ni(II) atom is six-coordinated by one N atom from a 1H-benzimidazole-5,6-dicarboxyl-ate ligand and by five O atoms from five water mol-ecules and displays a distorted octa-hedral geometry. Inter-molecular O-H⋯O hydrogen-bonding inter-actions among the coordinated water mol-ecules, solvent water mol-ecules and carboxy...

The asymmetric unit of the title compound, C(7)H(6)O(4)·C(5)H(5)N, consists of one 3,4-dihy-droxy-benzoic acid and one pyridine mol-ecule, both located on general positions. The 3,4-dihy-droxy-benzoic acid mol-ecules are arranged in layers and are connected by inter-molecular O-H⋯O hydrogen bonding, forming channels along the a axis in which the pyridine mol-ecules are located. The pyridine and...