Crystal structure of a tetranuclear CuII complex with an O,N,N′-donor Schiff base ligand: hexa-μ2-acetato-bis(2-{[(2,2,6,6-tetramethylpiperidin-4-yl)imino]methyl}phenolato-κ3O,N,N′)tetracopper(II)

Abstract

The title compound, [Cu4(CH3COO)6(C16H23N2O)2], lies across a twofold rotation axis. The asymmetric unit contains two independent CuII ions. The symmetry-unique terminal CuII ion is O,N,N′-coordinated by a 2-{[(2,2,6,6-tetramethylpiperidin-4-yl)imino]methyl}phenolate ligand and an O atom from an acetate group in a slightly distorted square-planar coordination environment. The symmetry-unique central CuII 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 intramolecular N—H...O hydrogen bonds. In the crystal, weak C—H...O hydrogen bonds link the complex molecules, forming a three-dimensional network.

Keywords

• crystal structure
• Schiff base ligand
• boat conformation
• piperidines
• copper(II) complex