Poly[tetra-aqua-bis-(µ(3)-oxalato-κ(5)O(1),O(2):O(1'):O(1'),O(2'))(µ(2)-oxalato-κ(4)O(1),O(2):O(1'),O(2'))dipraseodymium(III)].

In the title complex, [Pr(2)(C(2)O(4))(3)(H(2)O)(4)](n), the two independent Pr(III) ions are both nine-coordinated in a distorted monocapped square-anti-prismatic geometry by seven O atoms from four oxalate ligands and two water mol-ecules. The Pr(III) ions are bridged by the oxalate ligands, forming a layer parallel to (001). O-H⋯O hydrogen bonds connect the layers.

Diaqua-bis-(4-carb-oxy-2-ethyl-1H-imidazole-5-carboxyl-ato-κN,O)zinc N,N-dimethyl-formamide disolvate.

In the title compound, [Zn(C(7)H(7)N(2)O(4))(2)(H(2)O)(2)]·2C(3)H(7)NO, the Zn(II) ion, which lies on a center of inversion, is coordinated by two O atoms and two N atoms from two 4-carboxy-2-ethyl-1H-imid-azole-5-carboxyl-ato anions and two water O atoms in an octa-hedral environment, Each 4-carboxy-2-ethyl-1H-imid-azole-5-carboxyl-ato ligand adopts a bidentate chelating mode to the Zn(II) ion, forming two five-membered metalla rings. In the crystal, a two-dimensional framework parallel to (010) is formed by N-H⋯O and O-H⋯O hydrogen bonds.

3,3'-(5,5,7,12,12,14-Hexa-methyl-1,4,8,11-tetra-azacyclo-tetra-decane-1,8-diyl)di-propanonitrile methanol disolvate.

The asymmetric unit of the title compound, C(22)H(42)N(6)·2CH(4)O, comprises one half of a 14-membered tetra-azacyclo-tetra-decane macrocycle with cyano-ethyl substituents on one of the N atoms and a methanol solvent mol-ecule. The macrocycle lies about an inversion centre. The cyano-ethyl substituents are oriented so that the cyano groups lie over opposite faces of the central cavity of the macrocycle. The methanol solvate mol-ecules lie away from the cavity of the macrocycle and are linked to the macrocycles via O-H⋯N hydrogen bonds.

Hexaaqua-manganese(II) 4,4'-(1,2-dihy-droxy-ethane-1,2-di-yl)dibenzoate monohydrate.

In the title compound, [Mn(H(2)O)(6)](C(16)H(12)O(6))·H(2)O, the [Mn(H(2)O)(6)](2+) complex cation lies on a mirror plane, the 4,4'-(1,2-dihy-droxy-ethane-1,2-di-yl)dibenzoate anion is located on an inversion center and the solvent water mol-ecule also lies on a mirror plane. Extensive O-H⋯O hydrogen-bonding inter-actions between the cations, anions and water mol-ecules stabilize the three-dimensional network.

Diaqua-bis-(4-carb-oxy-2-propyl-1H-imidazole-5-carboxyl-ato-κN,O)zinc(II) N,N-dimethyl-formamide disolvate.

In the crystal structure of the title compound, [Zn(C(8)H(9)N(2)O(4))(2)(H(2)O)(2)]·2C(3)H(7)NO, the Zn(II) atom is coordinated by two N,O-bidentate 2-propyl-1H-imidazole-4,5-dicarboxyl-ate anions and two water mol-ecules in a distorted octa-hedral environment. The asymmetric unit consists of one Zn(II) atom located on a center of inversion as well as one anion, one water mol-ecule and one additional dimethyl-formamide mol-ecule that occupy general positions. Between the carboxyl and the carboxyl-ate group an intra-molecular hydrogen bond is found in which the hydroxy H atom is disordered. Disorder is also found for the H atoms of one of the three methyl groups. In the crystal structure, additional inter-molecular N-H⋯O and O-H⋯O hydrogen bonding is found.

Hexaaqua-zinc(II) 4,4'-(1,2-dihy-droxy-ethane-1,2-di-yl)dibenzoate monohydrate.

The title compound, [Zn(H(2)O)(6)](C(16)H(12)O(6))·H(2)O, consists of one 4,4'-(1,2-dihy-droxy-ethane-1,2-di-yl)dibenzoate anion lying on an inversion centre, one [Zn(H(2)O)(6)](2+) dication lying on a mirror plane and one solvent water mol-ecule located on a mirror plane. The octahedral [Zn(H(2)O)(6)](2+) cations, solvent water mol-ecules and anions inter-act via O-H⋯O hydrogen bonds, forming a three-dimensional network.

3-Nitro-5-(4-pyridinio)benzoate.

The title compound, C(12)H(8)N(2)O(4), crystallizes as a zwitterion in which the pyridyl N atom is protonated. The dihedral angle between the benzene and pyridinium rings is 27.9 (2)°. In the crystal, N-H⋯O hydrogen bonds link adjacent zwitterions into a three-dimensional structure.

[Bis(3,5-dimethyl-pyrazol-1-yl)methane]{N-[1-(2-oxidophen-yl)ethyl-idene]-dl-alaninato}copper(II) monohydrate.

In the title compound, [Cu(C(11)H(11)NO(3))(C(11)H(16)N(4))]·H(2)O, the Cu(II) atom is five-coordinate in a distorted square-pyramidal geometry. The basal positions are occupied by three donor atoms from the tridentate Schiff base ligand and by one N atom from a bis-(3,5-dimethyl-prazol-l-yl)methane ligand. The apical position is occupied by the N atom of the other ligand of this type. There are only van der Waals contacts in the crystal structure.

N'-(3-Bromo-5-chloro-2-hydroxy-benzyl-idene)-4-hydr-oxybenzohydrazide.

The mol-ecule of the title compound, C(14)H(10)BrClN(2)O(3), is planar [dihedral angle between the aromatic rings = 3.0 (2)°] and shows a trans configuration with respect to the C=N double bond. The crystal structure is stabilized by inter-molecular N-H⋯O hydrogen bonds and an intramolecular O-H⋯N interaction also occurs.