Xu-Cheng Fu

Poly[tetraaquadi-μ3-malonato-calcium(II)zinc(II)]

The title complex, [CaZn(C3H2O4)2(H2O)4]n, is a two-dimensional polymer and consists of CaO8 and ZnO6 polyhedra linked together by malonate ligands. The Ca(II) cation, lying on a twofold axis, is coordinated by two water molecules and six malonate O atoms. The Zn(II) cation, which lies on an inversion center in an octahedral environment, is coordinated by four malonate O atoms in an equatorial arrangement and two water molecules in axial positions. The Zn-O and Ca-O bond lengths are in the ranges 2.0445 (12)-2.1346 (16) and 2.3831 (13)-2.6630 (13) angstroms, respectively. The structure comprises alternating layers along the [101] plane, the shortest Zn...Zn distance being 6.8172 (8) angstroms. The whole three-dimensional structure is maintained and stabilized by the presence of hydrogen bonds.

Diaquamalonato(1,10-phenanthroline)zinc(II)

In the crystal structure of the title complex, [Zn(C3H2O4)(C12H8N2)(H2O)2], the Zn(II) atom displays a distorted octahedral geometry, being coordinated by two N atoms from the 1,10-phenanthroline ligand, two O atoms from different carboxylate groups of the chelating malonate dianion and two O atoms of cis water molecules. The complex molecules are linked to form a three-dimensional supramolecular array by both hydrogen-bonding interactions between coordinated water molecules and the uncoordinated carboxylate O atoms of neighboring molecules, and aromatic pi-pi stacking interactions between neighboring phenanthroline rings.

Poly[[aquatetraimidazoledi-μ-phthalato-dicopper(II)] monohydrate]

The title complex, ([Cu2(C 8 H 4 O 4 )2(C 3 H 4 N 2 )4(H20)] H 2 O] n , is a three-dimensional polymer formed through bridging by phthalate dianions of two different Cu II cations and a network of O(N)-H···O hydrogen bonds. The Cu-O and Cu-N interaction distances are in the ranges 2.0020 (16)-2.4835 (17) and 1.968 (2)-1.9855 (19) A, respectively. The structure is composed of alternating polymer chains parallel to the c axis, with a shortest Cu···Cu distance of 6.3000 (5) A.

A new polymorph of poly[tetra­aquadi-μ3-malonato-dicadmium(II)]

The crystal structure of the title compound, [Cd2(C3H2O4)2(H2O)4]n, was previously reported by Chung, Hong, Do & Moon [J. Chem. Soc. Chem. Commun. (1995), pp. 2333–2335; J. Chem. Soc. Dalton Trans. (1996), pp. 3363–3369]. We present here a new monoclinic polymorph which has a polymeric structure in which one Cd atom lies on an inversion centre and the other on a crystallographic twofold rotation axis.