Structure and properties of cobalt ortho-phenylenediacetate coordination polymers with rigid dipyridyl ligands

Divalent cobalt coordination polymers containing both ortho-phenylenediacetate (ophda) and rigid dipyridyl ligands 4,4′-bipyridine (bpy) or 1,2-bis(4-pyridyl)ethylene (dpee) display different topologies depending on carboxylate binding mode, tether length, and inclusion of charged species. [Co(ophda)(H2O)(dpee)]n (1) displays a common (4,4) grid layer motif. Use of the shorter bpy tether afforded {[Co2(ophda)2(bpy)3(H2O)2][Co(bpy)2(H2O)4](NO3)2·2bpy·7H2O}n (2) or [Co(ophda)(bpy)]n (3) depending on cobalt precursor. Compound 2 manifests 5-connected [Co2(ophda)2(bpy)3(H2O)2]n pillared bilayer slabs with rare 4862 SnS topology and entrained [Co(bpy)2(H2O)4]2+ complex cations. The 3-D coordination polymer 3 has an uncommon 4,6-connected binodal (4462)(446108) fsc topology, and shows ferromagnetic coupling (J = +1.5(2) cm−1) along 1-D spiro-fused [Co(OCO)2]n chain submotifs.

Cobalt coordination polymers with ortho-phenylenediacetate (ophda) and rigid dipyridyl ligands display different topologies: grids, 5-connected pillared bilayer slabs, and an uncommon 4,6-connected binodal (4462)(446108) fsc topology. Compound 3 shows ferromagnetic coupling along 1-D chain submotifs.Figure optionsDownload as PowerPoint slideHighlights
► Cobalt ortho-phenylenediacetate (ophda) coordination polymers.
► Anion-dependent rare bilayer slab and 4,6-connected binodal topologies.
► Ferromagnetic coupling along 1-D spiro-fused [Co(OCO)2]n chain submotifs.