Crystal structure, Hirshfeld surface analysis and DFT studies of tetra­kis­(μ-3-nitro­benzoato-κ(2) O (1):O (1′))bis­[(N,N-di­methyl­formamide-κO)copper(II)] di­methyl­formamide disolvate

The title compound, [Cu(2)(C(7)H(4)NO(4))(4)(C(3)H(7)NO)(2)]·(C(3)H(7)NO)(2), 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(II) cation, two 3-nitro­benzoato ligands, and two di­methyl­formamide (DMF) mol­ecules, one of which coordinates to the Cu(II) cation and one is a solvate mol­ecule. The carboxyl­ate groups of the ligands bridge two Cu(II) cations with a Cu—Cu distance of 2.6554 (6) Å, completing a distorted octa­hedral O(5)Cu coordination environment. The dihedral angles between the carboxyl­ate and the aromatic ring planes of the two independent ligands are different from one another, viz. 5.2 (3) and 23.9 (3)°. The three-dimensional structure is consolidated by weak C—H⋯O inter­actions and stabilized by π–π stacking inter­actions 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 mol­ecular orbitals of the complex were determined by DFT calculations at the B3LYP/def2-TZVP level of theory.