STEREOCHEMISTRY OF BIS(SALICYLALDIMINATO)METAL(II) COMPOUNDS, .2. CRYSTAL AND MOLECULAR-STRUCTURE OF A BINUCLEAR NICKEL(II) COMPOUND WITH A BRIDGING WATER MOLECULE [NI2(C14H11N2O4)4.H2O].2H2O

Yellow-green crystals of a 'sesquihydrate' of bis[N-(4-methoxyphenyl)-5-nitrosalicylideneiminato]nickel(II) are monoclinic, a = 17.04(3), b = 20.16(2), c = 36.44(6) », β = 99.42(1)°, space group C2/c. A three-dimensional X-ray analysis of the structure was made with counter data (2803 unique reflexions). The structure was solved by the heavy-atom method and refined by block-diagonal least-squares to a final R of 0.081 (R′ = 0.1079. Two octahedral [NiN2O4] polyhedra are linked facially through two bridging phenolic oxygens and a water molecule. Two other water molecules are hydrogen-bonded to both the bridging water, and to phenolic oxygens of the Schiff base ligands, forming a compact unit [Ni2[Schiff base)4(H2O)]·2H2O. The nickel polyhedra are markedly distorted because of ligand constraints: bond angles at the nickels range from 74 to 104°, and the bond lengths from the nickels to the bridging water oxygen are rather long at 2.24(1) and 2.30(1) Å. © 1979.