CRYSTAL STRUCTURE OF NICKEL(II) AND COBALT(II) ADDUCTS WITH 3-IMIDAZOLINE NITROXIDE. N.V. Pervukhina, A.B.Burdukov, V.I. Ovcharenko, Institute of Inorganic Chemistry Sib. Branch RAS, Novosibirsk, Russia, International Tomography Center Sib. Branch RAS, Novosibirsk, Russia
The crystal and molecular structures of novel compound Ni(hfac)2(H2O)2L2 (hfac=hexafluoroacetylacetonato-, L=2,2-dimethyl-5,5-dimethoxy-4-phenyl-3-imidazoline-1-oxyl) have been determined by single-crystal X-ray analysis ('SYNTEX P21', MoK, /2-scan). The coordination polyhedron of the nickel atom is formed by four hfac oxygen atoms (Ni-O 2.009(2)-2.036(2) Å) and two water oxygens (Ni-O 2.075(3) and 2.029(3) Å) which comprise almost regular octahedron. The nitroxide moieties L do not participate in coordination but form the H-bonds with coordinated water molecules (N***H 2.01, 1.93 Å and O(CH3)***H 2.00, 1.97 Å), therefore joining Ni(hfac)2(H2O)2 fragments in extended structure. The crystals of Ni(hfac)2(H2O)2L2 are orthorhombic, space group P212121, with 8 molecules on unit cell of dimensions a=11.625(3) Å, b=19.467(7), c=19.547(8) Å, V=4423.5(3) Å3, Dc=1.513 g*cm-3, 1272 unique Ihkl >2I, R=0.0458). The complex Co(hfac)2(H2O)2L2 is isostructural to Ni(hfac)2(H2O)2L2 according to powder diffraction data.