Crystal structure, Hirshfeld surface analysis and DFT studies of tetra-kis-(μ-3-nitro-benzoato-κ : )bis-[(,-di-methyl-formamide-κ)copper(II)] di-methyl-formamide disolvate.

The title compound, [Cu(CHNO)(CHNO)]·(CHNO), is a binuclear copper(II) complex located on an inversion center midway between the two copper(II) cations. The asymmetric unit consists of one Cu cation, two 3-nitro-benzoato ligands, and two di-methyl-formamide (DMF) mol-ecules, one of which coordinates to the Cu cation and one is a solvate mol-ecule. The carboxyl-ate groups of the ligands bridge two Cu cations with a Cu-Cu distance of 2.6554 (6) Å, completing a distorted octa-hedral OCu coordination environment. The dihedral angles between the carboxyl-ate and the aromatic ring planes of the two independent ligands are different from one another, . 5.2 (3) and 23.9 (3)°. The three-dimensional structure is consolidated by weak C-H⋯O inter-actions and stabilized by π-π stacking inter-actions between the aromatic rings. The complex and the free ligand were further characterized by Fourier-transform infrared spectroscopy (FT-IR), and the energies of the frontier mol-ecular orbitals of the complex were determined by DFT calculations at the B3LYP/def2-TZVP level of theory.