Cobalt phenylenediacetate coordination polymers containing long-spanning dipyridyl ligands: rectangular grid, primitive cubic, and 5-connected Archimedean layered net topologies

Divalent cobalt coordination polymers containing both phenylenediacetate (phda) and bis(4-pyridylmethyl)piperazine (4-bpmp) ligands display differing dimensionalities and topologies. The para-substituted 1,4-phda ligand afforded {[Co(1,4-phda)(4-bpmp)(H2O)(2)]center dot 2H(2)O}(n) (1), a layered phase with standard (4,4) rhomboid grid topology. Use of the meta-substituted 1,3-phda ligand lgenerated [Co(1,3-phda)(4-bpmp)](n) (2), which has [Co(1,3-phda)](n) layers pillared by pairs of 4-bpmp ligands into a three-dimensional (3D) coordination polymer with primitive cubic topology. Antiferromagnetically coupled {Co-2(CO2)(2)} dinuclear units (J = -2.04(4) cm(-1)) are embedded within the structure of 2. The ortho-substituted derivative {[Co(1,2-phda)(4-bpmp)(1.5)(H2O)](H(2)4-bpmp)(0.5)(ClO4)center dot 12H(2)O}(n) (3) manifests an intriguing layered structure with 5-connected cobalt atom nodes and an Archimedean 3(3)4(4)5(3) cem topology with triangular and rectangular circuits.