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

Abstract

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)(H 2O)(dpee)] n ( 1) displays a common (4,4) grid layer motif. Use of the shorter bpy tether afforded {[Co 2(ophda) 2(bpy) 3(H 2O) 2][Co(bpy) 2(H 2O) 4](NO 3) 2·2bpy·7H 2O} n ( 2) or [Co(ophda)(bpy)] n ( 3) depending on cobalt precursor. Compound 2 manifests 5-connected [Co 2(ophda) 2(bpy) 3(H 2O) 2] n pillared bilayer slabs with rare 4 86 2 SnS topology and entrained [Co(bpy) 2(H 2O) 4] 2+ complex cations. The 3-D coordination polymer 3 has an uncommon 4,6-connected binodal (4 46 2)(4 46 108) fsc topology, and shows ferromagnetic coupling ( J = +1.5(2) cm −1) along 1-D spiro-fused [Co(OCO) 2] n chain submotifs.