Crystal structure of tetrakis[μ-2-(methoxycarbonyl)benzoato-κ2O1:O1′]bis[(N,N-dimethylformamide-κO)copper(II)](Cu—Cu) dimethylformamide disolvate

Abstract

The title compound, [Cu2(C9H7O4)4(C3H7NO)2]·2C3H7NO, crystallizes in the monoclinic P21/c space group, with the binuclear copper unit occupying a special position on an inversion center, i.e. the asymmetric unit of the crystal consists of one CuII ion, two 2-(methoxycarbonyl)benzoate ligands, and two DMF molecules (one coordinated and one solvate). The binuclear complex displays a paddle-wheel-shaped structure with the two copper atoms being in a Jahn–Teller-distorted octahedral coordination environment. Each 2-(methoxycarbonyl)benzoate substituent acts as a bridging ligand and links two Cu atoms with a Cu—Cu distance of 2.633 (1) Å. The carboxylate groups of the 2-(methoxycarbonyl)benzoate ligands adopt bidentate syn–syn bridging modes, with dihedral angles between the carboxylate planes and the aromatic rings of 18.427 (4) and 43.029 (6)°. In the crystal, adjacent DMF molecules coordinated to copper atoms are arranged in a mutual `head-to-tail' manner by offset face-to-face π–π stacking interactions, resulting in chains along the c-axis direction. The planes of the coordinated DMF molecules are parallel to each other, the distance between them being 3.33 (1) Å. A three-dimensional structure is assembled from the chains by weak C—H...O and C—H...π intermolecular interactions involving the DMF solvent molecules. One of the methyl ester groups is disordered over two sites with an occupancy ratio of 0.751 (12):0.249 (12).

Keywords

• 2-(methoxycarbonyl)benzoate
• binuclear copper compound
• supramolecular structure
• π–π stacking interactions
• crystal structure