Crystal structure of tetrakis(μ-2,4,6-trimethyl-benzoato-κ²O:O')bis[(nicotinamide-κn¹)copper(II)]

In the title binuclear Cu^II complex, [Cu₂(C₁₀H₁₁O₂)₄(C₆H₆N₂O)₂], the two Cu^II cations [Cu···Cu = 2.5990 (5) Å] are bridged by four 2,4,6-trimethylbenzoate (TMB) anions. The four nearest O atoms around each Cu^II cation form distorted square-planar arrangements and the distorted square-pyramidal coordinations are completed by the pyridine N atoms of nicotinamide molecules at distances of 2.164 (2) and 2.165 (2) Å, respectively. The Cu^II cations are displaced by -0.2045 (3) and 0.2029 (3) Å from the corresponding planes formed by the nearest four O atoms. In the molecule, the dihedral angles between the planes of the benzene rings and the adjacent carboxylate groups are 80.6(2), 51.4(2), 24.4 (2) and 32.5 (2)°, while the planes of the pyridine rings are oriented at a dihedral angle of 11.28 (10)°. In the crystal, bifurcated N-H···O and weak C-H···O hydrogen bonds link the molecules, enclosing R²₂(8) and R⁴₄(8) ring motifs, into a three-dimensional network. The structure contains a solvent-accessible void of 72 ų, but there is no solvent molecule located within this void. The crystal studied was an inversion twin refined with a minor component of 0.488 (8).