Mono- and trinuclear nickel(II) complexes with sulfur-containing oxime ligands: Uncommon templated coupling of oxime with nitrile

4,7-Dithiadecane-2,9-dione dioxime forms both violet and purple-black nicke l(Il) complexes with unexpected structural properties, quite unlike the squ are-planar chelates formed by its dithiaundecane homologue. Their perchlora te salts were isolated and examined crystallographically. The lilac product [Ni{(Dtox)(CH3CNH)(2)}](ClO4)(2) entails a bis(iminoether) ligand formed b y coupling of the dioxime with two moles of acetonitrile. The purple-black complex results from further ligand deprotonation, to yield trinuclear, ant iferromagnetic [Ni-3(Dtox)(DtoxH)(2)](ClO4)(2). CH3CN, which maintains its structure in solution. The first one-electron electrochemical oxidation ste p is relatively facile for the trimer, yielding a (Ni2NiIII)-Ni-II complex, whereas for [Ni{(Dtox)(CH3CNH)(2)}](ClO4)(2) a transient Ni(I) species is accessible. Comment is made on those properties (coordination number, donor type, core charge) of nickel(II) coordination spheres that affect the acce ssibility of the corresponding nickel(I) and nickel(III) forms. [Ni-3(Dtox) (DtoxH)(2)](ClO4)(2). CH3CN crystallizes in the monoclinic space group P2(1 )/n, with cell parameters a = 12.295(2) Angstrom, b = 17.360(2) Angstrom, c = 20.764(2) Angstrom, alpha = 90 degrees, beta = 94.080(10)degrees, gamma = 90 degrees, V = 4420.7(6) Angstrom(3), Z = 4. [Ni{(Dtox)(CH3CNH)(2)}](ClO 4)(2) crystallizes in the rhombohedral space group <R(3)over bar>, with cel l parameters a 32.954(2) Angstrom, b = 32.954(2) Angstrom, c = 13.477(2) An gstrom, alpha = 90 degrees, beta = 90 degrees, gamma = 120 degrees, Z = 18.