Coordination polymers of flexible polycarboxylic acids with metal ions. V. polymeric frameworks of 5-(3,5-dicarboxybenzyloxy)-3-pyridine carboxylic acid with Cd(ii), Cu(ii), Co(ii), Mn(ii) and Ni(ii) ions; synthesis, structure, and magnetic properties

Abstract

Five new framework solids consisting of coordination polymers [Cd₃(L)₂(H₂O)₂(DMA)₂(H₂O)]_n (1), [Cu₃(L)₂(H₂O)₂]_n (2), [Co₃(L)₂(H₂O)₆]_n (3), [Mn₃(L)₂(H₂O)₅(DMF)]_n (4), and [Ni₃(L)₂(H₂O)₆]_n (5) (H₃L = 5-(3,5-dicarboxybenzyloxy)-3-pyridine carboxylic acid; DMA = dimethyl acetamide; DMF = dimethyl formamide) have been synthesized under hydro(solvo)thermal conditions and characterized by X-ray crystallography. The five compounds represent extended coordination-polymeric assemblies; double interweaving of the metal–organic frameworks has been observed in 3–5. A diverse metal–ligand coordination schemes have been observed, mono- (in 2–5), di- (in 2) and tri-nuclear (in 1). Thermal analysis (TGA and DTA) features of 1–5 and solid-state variable temperature magnetic susceptibility data of 3, 4 and 5 are reported as well. The magnetic susceptibility data reveal weak anti-ferromagnetic coupling between the metal centers in these complexes.