Crystal structure of a binuclear nickel(II) complex constructed of 1H-imidazo[4,5-f][1,10]phenanthroline and doubly deprotonated benzene-1,3,5-tricarboxylic acid

Abstract

The title complex, [Ni2(C9H4O6)2(C13H8N4)2(H2O)4]·2H2O, bis(μ-5-carboxybenzene-1,3-dicarboxylato-κ2O1:O1′)bis[diaqua(1H-imidazo[4,5-f][1,10]phenanthroline-κ2N7,N8)nickel(II)] dihydrate, was obtained under solvothermal conditions by the reaction of benzene-1,3,5-tricarboxylic acid (H3BTC) with Ni(NO3)2in the presence of 1H-imidazo[4,5-f][1,10]phenanthroline (IP). The crystal has triclinic (P-1) symmetry with a centrosymmetric binuclear nickel(II) cluster. The NiIIatom is coordinated by two N atoms from a chelating 1H-imidazo[4,5-f][1,10]phenanthroline ligand, two carboxylate O atoms from two 5-carboxybenzene-1,3-dicarboxylate ligands and two water molecules in a slightly distorted octahedral geometry. Two carboxylate groups bridge two NiIIcations, forming the binuclear complex. Extensive N—H...O, O—H...O and O—H...N hydrogen bonding is present in the crystal structure, forming a three-dimensional supermolecular framework. Weak π–π stacking is observed between parallel HBTC2−and IP ring systems, the face-to-face separation being 3.695 (2) Å.