Two nickel(II) bis­[(pyridin-2-yl)meth­yl]amine complexes with homophthalic and benzene-1,2,4,5-tetra­carb­oxy­lic acids

Two new Ni^II complexes are presented, i.e. a one-dimensional polymeric complex incorporating homophthalate, where the anion acts as the bridging ligand, and a complex incorporating benzene-1,2,4,5-tetra­carboxyl­ate, with two independent Ni centres in different environments, one of them a centrosymmetric 4- dinuclear complex and the other a 2+ mononuclear unit, appearing in a 1:2 ratio. The supra­molecular structure is supported by a profuse hydrogen-bonding network.