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]·2H2O}n (1), a layered phase with standard (4,4) rhomboid grid topology. Use of the meta-substituted 1,3-phda ligand generated [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 {Co2(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)](H24-bpmp)0.5(ClO4)·12H2O}n (3) manifests an intriguing layered structure with 5-connected cobalt atom nodes and an Archimedean 334453cem topology with triangular and rectangular circuits.