SYNTHESIS, STRUCTURE AND CHARACTERIZATION OF DINUCLEAR NICKEL(II) COMPLEXES CONTAINING THE DERIVATIVES OF ENZIMIDAZOLYL)METHYL]-2-HYDROXY-1,3-DIAMINOPROPANE AND AN ACETATE OR A PROPIONATE ION

The dinuclear nickel(II) complexes [Ni-2(L-1)(OAc) (H2O)(2)] (ClO4)(2) . 3H(2)O (1), [Ni-2(L-2)(OAc) (H2O)(2)] (ClO4)(2) (2) and [Ni-2(L-2)(O Pr) (H2O)(2)] (ClO4)(2). H2O (3) (HL1 = N,N,N',N'-tetrakis [ (1-methyl -2-benzimidazolyl) methyl] -2-hydroxy-1,3-diaminopropane, benzimidazoy l)methyl]-2-hydroxy-1,3-diaminpropane, OPr=propionate anion) were synt hesized and characterized. The crystal structures of [Ni-2(L-2)(OAc) ( CH3OH)(2)] (ClO4)(2). CH3OH . H2O (2') and [Ni-2(L-2)(OPr)-(CH3OH)(2)] (ClO4)(2). CH3OH . 2H(2)O (3'), which become 2 and 3 upon exposure of 2' and 3' to air, respectively, were determined by X-ray diffraction. 2' and 3' are isostructural. They consist of dinuclear cations and un coordinated perchlorate ions. In the complex cations, the two nickel(I I) centers are in a distorted octahedral coordination with an alkoxo a nd an acetato or a propionato bridge. The distances between the two ni ckel(II) ions are 3.521(2) and 3.507(2) A for 2' and 3', respectively. Variable temperature magnetic susceptibility measurements of 2 and 3 show an antiferromagnetic exchange coupling (2J= -43.2 cm(-1) for 2, a nd 2J= -34.4 cm(-1) for 3, H= -2JS(1). S-2) between two nickel(II) ion s. (C) 1998 Elsevier Science S.A. All rights reserved.