Crystal structure and Hirshfeld surface analysis of a copper(II) complex containing 2-nitro-benzoate and tetra-methyl-ethylenedi-amine ligands.

The reaction of copper(II) sulfatepentahydrate with 2-nitro-benzoic acid and N , N , N ', N '-tetra-methyl-ethylenedi-amine (TMEDA) in basic solution produces the complex bis-(2-nitro-benzoato-κ O )( N , N , N ', N '-tetra-methyl-ethylenedi-amine-κ ² N , N ')copper(II), [Cu(C ₇ H ₄ NO ₄ ) ₂ (C ₆ H ₁₆ N ₂ )] or [Cu(2-nitro-benzoate) ₂ (tmeda)]. Each carboxyl-ate group of the 2-nitro-benzoate ligand is coordinated by Cu ^II atom in a monodentate fashion and two TMEDA ligand nitro-gen atoms are coordinate by the metal center, giving rise to a distorted square-planar coordination environment. In the crystal, metal complexes are linked by centrosymmetric C-H⋯O hydrogen bonds, forming ribbons via a R ₂ ² (10) ring motif. These ribbons are linked by further C-H⋯O hydrogen bonds, leading to two-dimensional hydrogen-bonded arrays parallel to the bc plane. Weak π-π stacking inter-actions provide additional stabilization of the crystal structure. Hirshfeld surface analysis, d _norm and two-dimensional fingerprint plots were examined to verify the contributions of the different inter-molecular contacts within the supra-molecular structure. The major inter-actions of the complex are O⋯H/H⋯O (44.9%), H⋯H (34%) and C⋯H (14.5%).
(© Kansiz et al. 2021.)