Crystal structures of two Cu compounds: -poly[[chlorido-copper(II)]-μ--[eth-oxy(pyridin-2-yl)methyl-idene]-'-[oxido(pyridin-3-yl)methyl-idene]hydrazine-κ ,',:''] and di-μ-chlorido-1:4κ :-2:3κ :-di-chlorido-2κ,4κ-bis[μ-eth-oxy(pyridin-2-yl)methano-lato-1:2:3κ :,:;1:3:4κ ::,]bis-[μ-eth-oxy(pyridin-2-yl)methano-lato-1:2κ ,:;3:4κ ,:]tetracopper(II).

Two Cu complexes [Cu(CHNO)Cl] , , and [Cu(CHNO)Cl] , , have been synthesized. In the structure of the mononuclear complex , each ligand is coordinated to two metal centers. The basal plane around the Cu cation is formed by one chloride anion, one oxygen atom, one imino and one pyridine nitro-gen atom.

Aqua-{2-(pyridin-2-yl)-N-[(pyridin-2-yl)methyl-idene]ethanamine-κ(3) N,N',N''}(sulfato-κ(2) O,O')copper(II) tetra-hydrate.

The title complex, [Cu(SO4)(C13H13N3)(H2O)]·4H2O, was obtained by mixing copper sulfate penta-hydrate and 2-(pyridin-2-yl)-N-(pyridin-2-yl-methyl-idene)ethanamine in eth-anol under reflux conditions. The Cu(II) ion shows a Jahn-Teller-distorted octa-hedral geometry, with equatorial positions occupied by three N atoms from the tridentate ligand (average Cu-N = 2.004 Å) and one O atom from a bidentate sulfate anion [Cu-O = 1.

Bis{2-amino-2-oxo-N-[(1E)-1-(pyridin-2-yl-κN)ethyl-idene]acetohydrazidato-κ(2)N',O(1)}nickel(II).

In the title compound, [Ni(C(9)H(9)N(4)O(2))(2)], the Ni(II) ion is situated on a twofold rotation axis and is coordinated by two O and four N atoms from two tridentate {2-amino-2-oxo-N-[(1E)-1-(pyridin-2-yl-κN)ethyl-idene]acetohydrazidate ligands in a distorted octa-hedral geometry. In the crystal, N-H⋯O and N-H⋯N hydrogen bonds link the mol-ecules into columns in [001]. The porous crystal packing is further stabilized via π-π inter-actions between the pyridine rings of neighbouring mol-ecules [centroid-centroid distance = 3.

Chlorido[N'-(2-oxidobenzil-idene)acetohydrazide-κO,N',O']copper(II) dihydrate.

In the title complex, [Cu(C(9)H(9)N(2)O(2))Cl]·2H(2)O, prepared from the Schiff base ligand N'-(2-hydroxy-benzil-idene)aceto-hydrazide and copper(II) chloride, the Cu(II) atom is coord-inated by two O atoms and one N atom from the ligand and by a Cl atom in a distorted square-planar geometry. The two donor O atoms of the tridentate Schiff base ligand are in a trans arrangement. In the crystal structure, there is an extensive inter-molecular hydrogen-bonding network; N-H⋯O, O-H⋯O and O-H⋯Cl inter-actions, involving the uncoordinated water mol-ecules, lead to the formation of a two-dimensional network parallel to the ab plane.

{μ-N,N'-Bis[1-(2-pyridyl)ethylidene]benzene-1,2-diamine}di-μ-chlorido-bis[diaquanickel(II)] dichloride ethanol disolvate.

In the title compound, [Ni(2)Cl(2)(C(20)H(18)N(4))(H(2)O)(4)]Cl(2)·2C(2)H(6)O, the coordination environment of each Ni(2+) ion is distorted octa-hedral formed by two N atoms from the Schiff base ligand, two O atoms from water mol-ecules and two chloride anions acting as μ(2) bridges between the metal ions. The coordinated water mol-ecules are linked to the uncoordinated ethanol mol-ecules and chloride anions by O-H⋯O and O-H⋯Cl hydrogen bonds, although the assignment of some of these is tentative. A weak inter-molecular O-H⋯N inter-action within the ligand is also observed.

The cocrystal μ-oxalato-κO,O:O,O-bis-(aqua-(nitrato-κO){[1-(2-pyridyl-κN)eth-ylidene]hydrazine-κN}copper(II)) μ-oxalato-κO,O:O,O-bis-((methanol-κO)(nitrato-κO){[1-(2-pyridyl-κN)eth-ylidene]hydrazine-κN}copper(II)) (1/1).

The title cocrystal, [Cu(2)(C(2)O(4))(NO(3))(2)(C(7)H(9)N(3))(2)(H(2)O)(2)][Cu(2)(C(2)O(4))(NO(3))(2)(C(7)H(9)N(3))(2)(CH(4)O)(2)], is a 1:1 cocrystal of two centrosymmetric Cu(II) complexes with oxalate dianions and Schiff base ligands. In each mol-ecule, the Cu(II) centre is in a distorted octa-hedral cis-CuN(2)O(4) environment, the donor atoms of the N,N'-bidentate Schiff base ligand and the bridging O,O'-bidentate oxalate group lying in the equatorial plane. In one mol-ecule, a monodentate nitrate anion and a water mol-ecule occupy the axial sites, and in the other, a monodentate nitrate anion and a methanol mol-ecule occupy these sites.