STRUCTURES OF DICHLOROBIS(TRIMETHYLAMINE OXIDE)COBALT(II), DIIODOBIS(TRIMETHYLAMINE OXIDE)COBALT(II), DICHLOROBIS(TRIMETHYLAMINE OXIDE)ZINC AND DIBROMOBIS(TRIMETHYLAMINE OXIDE)ZINC

[CoCl2(C3H9NO)2] (1), M(r) = 280.1, orthorhombic, Pna2(1), a = 40.800 (10), b = 10.882 (5), c = 10.966 (5) angstrom, V = 4868.7 (33) angstrom 3, Z = 16, D(m) = 1.47 (room temperature), D(x) = 1.53 (150 K) g cm-3, lambda(Mo K-alpha) = 0.71069 angstrom, mu = 18.26 cm-1, F(000) = 2320, T = 150 K, R = 0.0564 for 2605 observed reflections. The compound contains Co in four coordination, but the precise geometry varies somewhat over four molecules which are present in the asymmetric unit. The differences are reflected in significant variations in the Cl-Co-Cl and O-Co-O bond angles. [CoI2(C3H9NO)2] (2), M(r) = 462.95, orthorhombic, Pbcn, a = 11.742 (4), b = 11.291 (3), c = 10.404 (3) angstrom, V = 1379.4 (7) angstrom 3, Z = 4, D(m) = 2.15 (room temperature), D(x) = 2.23 (150 K) g cm-3, mu(Mo K-alpha) = 56.53 cm-1, F(000) = 868, T = 150 K, R = 0.0256 for 1424 observed reflections. The compound is a mononuclear tetrahedral Co complex with molecular symmetry C2. [ZnCl2(C3H9NO)2] (3), M(r) = 286.5, monoclinic, P2(1), a = 9.756 (3), b = 10.383 (3), c = 6.558 (2) angstrom, beta = 109.13 (2)-degrees, V = 627.6 (3) angstrom 3, Z = 2, D(m) = 1.47 (room temperature), D(x) = 1.52 (150 K) g cm-3, mu(Mo K-alpha) = 24.11 cm-1, F(000) = 296, T = 150 K, R = 0.0359 for 1704 observed reflections. The molecular symmetry approximates to C2. [ZnBr2(C3H9NO)2] (4), M(r) = 375.4, orthorhombic, Pbcn, a = 11.270 (3), b = 11.053 (3), c = 10.206 (3) angstrom, V = 1271.3 (6) angstrom 3, Z = 4, D(m) = 1.91 (room temperature), D(x) = 1.96 (150 K) g cm-3, mu(Mo K-alpha) = 81.85 cm-1, F(000) = 736, T = 150 K, R = 0.0447 for 1322 observed reflections. The compound is isomorphous with (2). The molecular packing in (2) and (4) is suited to the heavier halides, even though there are X...X intermolecular distances as low as ca 4.9 angstrom. With the chlorides, greater M-X bond polarity and the likelihood of shorter X...X distances causes development of alternative structures, as shown by (1) and (3).