Crystal structures of two Cu compounds: Catena-poly[[chloridocopper(II)]-μ-N-[ethoxy(pyridin-2-yl)methylidene]-N'-[oxido(pyridin-3-yl)methylidene]hydrazine-κ N,N',O:N''] and di-μ-chlorido-1:4κ Cl:Cl-2:3κ Cl:Cl-dichlorido-2κCl,4κCl-bis[μ3-ethoxy(pyridin-2-yl)methanolato-1:2:3κ O:N,O:O;1:3:4κ O:O:N,O]bis[μ2-ethoxy(pyridin-2-yl)methanolato-1:2κ N,O:O;3:4κ N,O:O]tetracopper(II)

Two Cu complexes [Cu(CH13N4O)Cl] n , I, and [Cu4(CH10NO)4Cl4] 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 cation is formed by one chloride anion, one oxygen atom, one imino and one pyridine nitrogen atom. The apical position of the distorted square-pyramidal geometry is occupied by a pyridine nitrogen 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 intermolecular C - H⋯O and C - H⋯Cl interactions, leading to a three-dimensional network structure. The tetranuclear complex II lies about a crystallographic inversion centre and has one core in which two Cu metal centers are mutually interconnected via two enolato oxygen atoms while the other two Cu 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 ions bridged by two enolato oxygen atoms acting in a μ3-mode. The Cu atoms in each of the two CuONCl units are connected by one μ2-O and two μ3-O atoms from deprotonated hydroxyl groups and one chloride anion to the three other Cu centres. Each of the pentacoordinated Cu cations has a distorted NOCl square-pyramidal environment. The Cu atoms in each of the two CuONCl2 units are connected by μ2-O and μ3-O atoms from deprotonated alcohol hydroxy groups and one chloride anion to two other Cu ions. Each of the pentacoordinated Cu cations has a distorted NOCl2 square-pyramidal environment. In the crystal, a series of intramolecular C - H⋯O and C - H⋯Cl hydrogen bonds are observed in each tetranuclear monomeric unit, which is connected to four tetranuclear monomeric units by intermolecular C - H⋯O hydrogen bonds, thus forming a planar two-dimensional structure in the ( 01) plane.