Crystal structures of two CuII compounds: catena-poly[[chlorido­copper(II)]-μ-N-[eth­oxy(pyridin-2-yl)methyl­idene]-N′-[oxido(pyridin-3-yl)methyl­idene]hydrazine-κ4N,N′,O:N′′] and di-μ-chlorido-1:4κ²Cl:Cl-2:3κ²Cl:Cl-di­chlorido-2κCl,4κCl-bis[μ3-eth­oxy(pyridin-2-yl)methano­lato-1:2:3κ³O:N,O:O;1:3:4κ³O:O:N,O]bis­[μ2-eth­oxy(pyridin-2-yl)methano­lato-1:2κ³N,O:O;3:4κ³N,O:O]tetracopper(II).

Two Cu^II complexes [Cu(C₁₄H₁₃N₄O₂)Cl]_n, I, and [Cu₄(C₈H₁₀NO₂)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^II 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—HO and C—HCl 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^II metal centers are mutually inter­connected 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 μ₃-mode. The Cu^II atoms in each of the two CuO₃NCl 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^II centres. Each of the penta­coordinated Cu^II cations has a distorted NO₃Cl square-pyramidal environment. The Cu^II atoms in each of the two CuO₂NCl₂ units are connected by μ₂-O and μ₃-O atoms from deprotonated alcohol hy­droxy groups and one chloride anion to two other Cu^II ions. Each of the penta­coordinated Cu^II cations has a distorted NO₂Cl₂ 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 (1...01) plane. [ABSTRACT FROM AUTHOR]