A DINUCLEAR NICKEL(II) COMPOUND - ETHYLENEDIAMINE)-BIS[AQUA(NITRATO-O,O')NICKEL(II)] DINITRATE DIMETHANOL SOLVATE

The title compound, i-2(NO3)(2)(C30H48N10)(H2O)(2)]-(NO3)(2).2CH(3)OH, contains a doubly charged cation which lies across an inversion cente r. The hexadentate ligand N,N,N',N'-tetrakis[2-(3,5-dimethyl-1-pyrazol yl)- ethyl]-1,2-ethylenediamine (tped) holds two Ni-II ions at a dista nce of 6.3721 (13) Angstrom. A distorted octahedron around each Ni-II ion is defined by two pyrazole N atoms of tped at distances of 2.023 ( 4) and 2.048 (4) Angstrom, one amine N atom of tped at a distance of 2 .161(4) Angstrom, two O atoms of a chelating nitrate anion at distance s of 2.144 (3) and 2.205 (4) Angstrom, and a water O atom at a distanc e of 2.032 (4) Angstrom. A one-dimensional hydrogen-bonding network ru nning along the a axis connects the methanol molecule of crystallizati on to the nitrate and aqua ligands of different cations, and an aqua l igand to the non-coordinated nitrate ion. The structure is essentially isomorphous with the previously reported Cu-II analog [Driessen, Haan stra & Reedijk (1992). Acta Cryst. C48, 1585-1587], the main differenc es being that NO3 is involved in bidentate coordination to Ni-II and i n a bifurcated hydrogen bond with methanol, whereas in the Cu-II compl ex, it is monodentate and only one of its O atoms hydrogen bonds to me thanol.