Crystal structure of a tetranuclear Cu(II) complex with an O,N,N'-donor Schiff base ligand: hexa-μ2-acetato-bis-(2-{[(2,2,6,6-tetra-methyl-piperidin-4-yl)imino]-meth-yl}phenolato-κ(3) O,N,N')tetra-copper(II).

The title compound, [Cu4(CH3COO)6(C16H23N2O)2], lies across a twofold rotation axis. The asymmetric unit contains two independent Cu(II) ions. The symmetry-unique terminal Cu(II) ion is O,N,N'-coordinated by a 2-{[(2,2,6,6-tetra-methyl-piperidin-4-yl)imino]-meth-yl}phenolate ligand and an O atom from an acetate group in a slightly distorted square-planar coordination environment. The symmetry-unique central Cu(II) ion is coordinated by a different O atom from the same acetate group and by four bridging acetate ligands, which connect the asymmetric unit into a dimeric complex and form a distorted square-pyramidal coordination environment. Within the complex there are two symmetry-equivalent intra-molecular N-H⋯O hydrogen bonds. In the crystal, weak C-H⋯O hydrogen bonds link the complex mol-ecules, forming a three-dimensional network.