Mononuclear and dinuclear bromide–nitrite cadmium(II) complexes with related 1,4-diazabicyclo[2.2.2]octane ligands
作者:Ying Cai
DOI:10.1107/s010827011005167x
日期:2011.1.15
The title compounds, di-mu-bromido-bis[bromido(1-carboxymethyl-4-aza-1-azoniabicyclo[2.2.2]octane-kappa N 4)(nitrito-kappa 2 O,O')cadmium(II)] dihydrate, [Cd(2)Br(4)(C(8)H(15)N(2)O(2))(2)(NO(2))(2)]center dot 2H(2)O, (I), and aquabromido(1-cyanomethyl-4-aza-1-azoniabicyclo[2.2.2]octane-kappa N 4)bis(nitrito-kappa 2 O,O')cadmium(II) monohydrate, [CdBr(C(8)H(14)N(3))(NO(2))(2)(H(2)O)]center dot H(2)O, (II), are two-dimensional hydrogen-bonded metal-organic hybrid complexes. In (I), the complex is situated on a centre of inversion so that each symmetry-related CdII atom is coordinated by two bridging Br atoms, one monodentate Br atom, one chelating nitrite ligand and one organic ligand, yielding a significantly distorted octahedral geometry. The combination of O-H...O and O-H...Br hydrogen bonds produces centrosymmetric R (6) 6(16) ring motifs, resulting in two-dimensional layers parallel to the ab plane. In contrast, the complex molecule in (II) is mononuclear, with the CdII atom seven-coordinated by two bidentate nitrite groups, one N atom from the organic ligand, one monodentate Br atom and a water O atom in a distorted pentagonal-bipyramidal environment. The combination of O-H...O and O-H...Br hydrogen bonds produces R (5) 4(14) and R (3) 3(8) rings which lead to two-dimensional layers parallel to the ac plane.