A double-layered zinc(II) coordination polymer with the ligand 3,5-bis(carboxylatomethoxy)benzoate.

In the title compound, poly[hexaaquabis[mu(4)-3,5-bis(carboxylatomethoxy)benzoato]trizinc(II)], [Zn(3)(C(11)H(7)O(8))(2)(H(2)O)(6)](n), there are two crystallographically distinct Zn(II) cations which are bridged by polycarboxylate ligands in a mu(4)-bridging mode. A pair of ligands bridges adjacent Zn atoms to give centrosymmetric dimetal building blocks which act as four-connected nodes to be further interlinked into a two-dimensional double-layered framework with (4,4) topology. Other Zn atoms, lying on inversion centres, occupy the cavities of this topological structure. This submission shows a versatile polycarboxylate ligand with rigid and flexible functional groups, the co-operation and complementarity of which would meet the coordination requirements of a variety of topological structures.

A coordination polymer of CdCl2 with the novel zwitterionic dicarboxylate ligand 2,2'-(2-methylbenzimidazolium-1,3-diyl)diacetate (pda).

The title compound, poly[chlorido[mu(4)-2,2'-(2-methylbenzimidazolium-1,3-diyl)diacetato]cadmium(II)], [Cd(C(12)H(11)N(2)O(4))Cl](n), is an undulating two-dimensional polymer consisting of a paddlewheel Cd(2)(CO(2))(4) cluster which lies on an inversion centre. These paddlewheel clusters act as four-connected square building units interlinked via bridging zwitterionic dicarboxylate ligands into a corrugated layer which is consolidated by pi-pi interactions between benzene rings of benzimidazole groups. Neighbouring layers are further assembled via interlayer pi-pi interactions into a three-dimensional supramolecular structure. The key feature of this study is the synthesis of a paddlewheel-based polymer constructed with a novel multifunctional zwitterionic dicarboxylate ligand.

catena-poly[[[pyridinecopper(II)]bis[mu3-4-(2-oxidobenzylideneamino)benzoato]] dimethylformamide disolvate], a polymer composed of dimeric dicopper building units.

The title compound, {[Cu(C(14)H(9)NO(3))(C(5)H(5)N)].C(3)H(7)NO}n or {[Cu(2)L(2)(py)(2)].2DMF}n [py is pyridine, L is 4-(salicylideneamino)benzoate and DMF is dimethylformamide], is composed of dimeric dicopper [CuL(py)]2 building units, which are interlinked into a one-dimensional chain through the formation of Cu-O(COO) bonds. The dimeric unit is centrosymmetric, containing two Cu(II) atoms linked by bridging phenolate O atoms into a Cu(2)O(2) plane with a chelating Cu-O bond length of 1.927 (2) A and a bridging Cu-O bond length of 2.440 (2) A. Interchain C-H...O and pi-pi stacking interactions are responsible for an extensive three-dimensional structure in which the resulting channels are filled by DMF solvent molecules.