COMPLEXES WITH DIIMINE LIGANDS .2. SYNTHESIS, STRUCTURE AND MAGNETIC STUDIES OF MIXED ACETYLACETONATENICKEL(II) DERIVATIVES

The synthesis, structure and magnetic properties of [Ni(L)(hfacac)2], [Ni(L)(tfacac)2], [Ni(BDPQ)(acac)2] where L is 2,3-bis(2-pyridyl)pyrazine (DPP), 2,3-bis(2-pyridyl)quinoxaline (DPQ), 6-methyl-2,3-bis(2-pyridyl)quinoxaline (MeDPQ), 6,7-dimethyl-2,3-bis(pyridyl)quinoxaline (DMeDPQ), 6-chloro-2,3-bis(2-pyridyl)quinoxaline (CIDPQ), 2,3-bis(2-pyridyl)benzoquinoxaline (BDPQ), hfacac, tfacac and acac are hexafluoroacetylacetonate, trifluoroacetylacetonate and acetylacetonate ions, respectively, and [Ni2(L')(acac)4] where L' is DPQ, MeDPQ and DMeDPQ, are described. The crystal structures of the BDPQ ligand and the [Ni(BDPQ)(hfacac)2] complex are also reported. The ligand BDPQ crystallizes in the triclinic space group P1BAR with cell parameters a = 16.990(3), b = 7.982(2), c = 6.197(2) angstrom, alpha = 96.74(2), beta = 94.89(3), gamma = 102.48(2)-degrees and Z = 2. The [Ni(BDPQ)(hfacac)2] complex crystallizes in the monoclinic space group P2(1)/a with a cell parameters a = 24.272(4), b = 15.222(3), c = 8.964(2) angstrom, beta = 97.61(3)-degrees and Z = 4. Two nickel-nitrogen (pyridine) bonds are present.