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

Two Cu(II) complexes [Cu(C(14)H(13)N(4)O(2))Cl] (n) , I, and [Cu(4)(C(8)H(10)NO(2))(4)Cl(4)] (n) , II, have been synthesized. In the structure of the mononuclear complex I, each ligand is coordinated to two metal centers. The basal plane around the Cu(II) cation is formed by one chloride anion, one oxygen atom, one imino and one pyridine nitro-gen atom. The apical position of the distorted square-pyramidal geometry is occupied by a pyridine nitro-gen atom from a neighbouring unit, leading to infinite one-dimensional polymeric chains along the b-axis direction. Each chain is connected to adjacent chains by inter-molecular C-H⋯O and C-H⋯Cl inter-actions, leading to a three-dimensional network structure. The tetra-nuclear complex II lies about a crystallographic inversion centre and has one core in which two Cu(II) metal centers are mutually inter-connected via two enolato oxygen atoms while the other two Cu(II) cations are linked by a chloride anion and an enolato oxygen. An open-cube structure is generated in which the two open-cube units, with seven vertices each, share a side composed of two Cu(II) ions bridged by two enolato oxygen atoms acting in a μ(3)-mode. The Cu(II) atoms in each of the two CuO(3)NCl units are connected by one μ(2)-O and two μ(3)-O atoms from deprotonated hydroxyl groups and one chloride anion to the three other Cu(II) centres. Each of the penta-coordinated Cu(II) cations has a distorted NO(3)Cl square-pyramidal environment. The Cu(II) atoms in each of the two CuO(2)NCl(2) units are connected by μ(2)-O and μ(3)-O atoms from deprotonated alcohol hy-droxy groups and one chloride anion to two other Cu(II) ions. Each of the penta-coordinated Cu(II) cations has a distorted NO(2)Cl(2) square-pyramidal environment. In the crystal, a series of intra-molecular C-H⋯O and C-H⋯Cl hydrogen bonds are observed in each tetra-nuclear monomeric unit, which is connected to four tetra-nuclear monomeric units by inter-molecular C-H⋯O hydrogen bonds, thus forming a planar two-dimensional structure in the (01) plane.