Tetra-kis[μ-4-(methyl-amino)-benzoato-κ² O:O′]bis-[(N,N-diethyl-nicotinamide-N ¹)zinc(II)] dihydrate

The title mol-ecule, [Zn₂(C₈H₈NO ₂)₄(C₁₀H₁₄N₂O) ₂]·2H₂O, is a centrosymmetric binuclear complex, with two Zn^II ions [Zn⋯Zn = 2.9301 (4) Å] bridged by four methyl-amino-benzoate (MAB) ligands. The four nearest O atoms around each Zn^II ion form a distorted square-planar arrangement with the distorted square-pyramidal coordination completed by the pyridine N atom of the N,N-diethyl-nicotinamide (DENA) ligand. Each Zn^II ion is displaced by 0.3519 (2) Å from the plane of the four O atoms, with an average Zn- O distance of 2.030 Å. The dihedral angles between carboxyl-ate groups and adjacent benzene rings are 10.57 (10) and 16.63 (12)°, while the benzene rings are oriented at a dihedral angle of 81.84 (5)°. The pyridine ring is oriented at dihedral angles of 40.49 (6) and 51.25 (6)° with respect to the benzene rings. In the crystal structure, inter-molecular O- H⋯O and N- H⋯O hydrogen bonds link the mol-ecules into a three-dimensional network. The π-π contact between the inversion-related pyridine rings [centroid-centroid distance = 3.633 (1) Å] may further stabilize the crystal structure.