One Dimensional Coordination Polymer of Nickel(II)-Squarate with N,N,N′,N′-tetramethylethylenediamine, {[Ni(μ-sq)(H2O)2(tmen)]·H2O}n

A novel 1D coordination polymer {[Ni(μ-sq)(H2O)2(tmen)]·H2O}n (H2sq = squaric acid and tmen = N,N,N′,N′-tetramethylethylenediamine) has been synthesized and structurally characterized by X-ray crystallography. The spectral (IR and UV-vis.) and magnetic susceptibility are reported. The structure of the complex consists of the bidentate tmen ligand bound to Ni(II) center and a bridging squarate in the 1,3-bonding mode. The distorted octahedral geometry of Ni(II) is completed by two aqua ligands. The structure contains chains of squarato-O1,O3-bridged polynuclear nickel(II) units held together by intermolecular hydrogen bonds interactions between water molecules and oxygen atoms of squarate ligand forming a novel R6 motif.