Wen-Shi Wu

(E)-2-(4-Chloro­phen­oxy)-N′-(pyridin-4-yl­methyl­idene)acetohydrazide

In the title compound, C14H12ClN3O2, the acylhydrazone base [C(=O)—N—N=C] is essentially planar, with an r.m.s. deviation of 0.0095 Å, and makes a dihedral angle of 12.52 (10)°with the pyridine ring. In the crystal, molecules are linked via pairs of N—H⋯O hydrogen bonds, forming inversion dimers with an R 2 2(8) graph-set motif. The dimers are linked via C—H⋯π interactions forming chains along [101].

Diethyl pyrazine-2,5-dicarboxyl­ate

The molecule of the title compound, C10H12N2O4, is located around an inversion center. The carboxylate groups are twisted slightly with respect to the pyrazine ring, making a dihedral angle of 2.76 (19)°. In the crystal, molecules are stacked along the c axis via weak C—H⋯O hydrogen bonds.

Aqua-[6-carboxyl-ato-N'-(pyridin-2-yl-methyl-idene)pyridine-2-carbohydrazidato]copper(II) trihydrate.

In the title compound, [Cu(C13H8N4O3)(H2O)]·3H2O, the complex molecule, except for the aqua ligand, is essentially planar [r.m.s. deviation = 0.034 (2) Å]. The coordination polyhedron of the Cu2+ cation is a square-pyramid, with the aqua ligand at the apex. The compound exhibits a three-dimensional structure, which is is stabilized by O—H⋯O and O—-H⋯N hydrogen bonds and π–π interactions [centroid–centroid distance = 2.987 (3) Å].

catena-Poly[[aqua-bromidocopper(II)]-μ(3)-(picolinato N-oxide)].

The title complex, [CuBr(C6H4NO3)(H2O)]n, exhibits a layered structure which is stabilized by intermolecular O—H⋯O and O—H⋯Br− hydrogen bonds, van der Waals forces and π–π interactions [centroid–centroid distance = 3.747(4) Å] between the parallel pyridine rings from two neighboring layers.

Bis[μ-N′-(2-oxidobenzyl­idene)thio­phene-2-carbohydrazidato]bis­[dimethanol­nickel(II)]

In the crystal structure of the centrosymmetric binuclear title complex, [Ni2(C12H8N2O2S)2(CH3OH)4], there are intermolecular O—H⋯O, O—H⋯N and O—H⋯S hydrogen bonds. These help to stabilize the structure and link the molecules, forming a three-dimensional network structure. The Ni2+ cation exists in a slightly distorted octahedral NiNO5 coordination environment. The thiophene rings are disordered over two equivalent conformations with occupancies of 0.881 (3) and 0.119 (3).

Diisopropyl pyrazine-2,5-dicarboxyl-ate.

The molecule of the title compound, C12H16N2O4, is located on an inversion center. The carboxylate groups are twisted slightly with respect to the pyrazine ring, making a dihedral angle of 6.4 (3)°.

4-Eth­oxy-N′-propanoylpyridine-2-carbohydrazide

In the crystal structure of the title compound, C11H15N3O3, molecules are linked into a chain by intermolecular N—H⋯O hydrogen bonds.

5,6-Dihydr-oxy-1,10-phenanthrolin-1-ium chloride dihydrate.

The title compound, C12H9N2O2 +·Cl−·2H2O, exhibits a layered structure which is stabilized by intermolecular O—H⋯O, O—H⋯Cl− and N+—H⋯Cl− hydrogen bonds, and π–π interactions (centroid–centroid distances = 3.654 and 3.583 Å). The distances between the molecules are 3.371 and 3.294 Å.

N2′,N5′-Diisopropylidene­pyrazine-2,5-dicarbohydrazide dihydrate

In the title compound, C12H16N6O2·2H2O, the organic molecule, except for the methyl H atoms, is essentially planar, the r.m.s. deviation from planarity being 0.044 Å. The crystal structure is stabilized by intermolecular O—H⋯O and O—H⋯N hydrogen bonds which form chains.