SYNTHESIS AND CRYSTAL-STRUCTURES OF NICKEL(II) AND COPPER(II) COMPLEXES OF MESO-3,6,6,9-TETRAMETHYL-4,8-DIAZAUNDECANE-2, 10-DIONE DIOXIME

The nickel(II) and copper(II) complexes of o-3,6,6,9-tetramethyl-4,8-d iazaundecane-2,10-dione dioxime (meso-HM-PAO) have an intramolecular h ydrogen bond between cis oxime groups. [Cu(meso-HM-PAO-H)(H2O)](NCS) c rystallizes in space group P2(1)/n with a = 7.692(1), b = 12.028(2), c = 20.235(3) angstrom, beta = 93.03(1)degrees, Z = 4 and Dc = 1.46 g/c m3. The final R value for this complex was 0.034 for 2223 observed ref lections with I greater-than-or-equal-to 2.5sigma (I). The Cu(II) coor dination is a distorted square pyramid. The Cu(II) ion is five-coorina ted with the diazadioxime N atoms equatorial and water O atom axial. T he Cu(II) is 0.12 angstrom from the equatorial plane towards the hydra te. The equatorial Cu-N distances span a narrow range, 1.953(3)-1.999( 3) angstrom. The axial Cu-O distance is 2.314(3) angstrom. The thiocya nate group is almost linear. The intramolecular O...O hydrogen bond le ngth is 2.479(4) angstrom. [Ni(meso-HM-PAO-H)](ClO4) crystallizes in s pace group P2(1)/c with a = 14.774(3), b = 12.752(3), c = 20.035(4) an gstrom, beta = 92.94(3)degrees, Z = 8 and Dc = 1.51 g/cm3. The final R value for the complex was 0.053 for 4794 observed reflections with F greater-than-or-equal-to 4sigma (F). The coordination about Ni(II) is a slightly distorted squire plane. The Ni(II) ion is 0.0673(7) angstro m from the best plane of the four donor nitrogen atoms away from the p erchlorate ion. The Ni-N distances span a narrow range 1.863(4) - 1.92 7(4) angstrom. There are two molecules per asymmetrical unit resulting in eight molecules being packed in an unit cell; they are bound toget her by van der Waals interactions. The O-H...O bonds of these complexe s give characteristic infrared absorptions as well as chemical shift o f the H-1 NMR signal (Ni complex).