A family of coordination polymers assembled with a flexible hexacarboxylate ligand and auxiliary N-donor ligands: syntheses, structures, and physical properties

Abstract

Nine new coordination polymers, namely, [Mn₅(HL)₂(H₂O)₂]·2C₂H₅OH·4H₂O (1), Mn₃(L)(phen)₂ (2), Mn₃(L)(2,2′-bpy)₂ (3), Cd₃(L)(2,2′-bpy)₂ (4), Cd₃(L)(phen)₂ (5), Co₂Na(HL)(phen)₂·0.5C₂H₅OH·H₂O (6), Co₃(L)(4,4′-bpy) (7), Cu₂(H₂L)(4,4′-bpy)₄·0.5H₂O (8) and Cu₂(H₂L)(ttp)₂·2C₂H₅OH·2H₂O (9), have been synthesized under hydrothermal conditions (H₆L = 1,2,3,4,5,6-hexakis(3-carboxyphenyloxymethylene)benzene, phen = 1,10-phenathroline, 2,2′-bpy = 2,2′-bipyridine, 4,4′-bpy = 4,4′-bipyridine and ttp = 2-(6-(pyridin-2-yl)-4-p-tolylpyridin-2-yl)pyridine). Compound 1 shows a 2D layer structure. Compounds 2–5 display similar 2D networks, which are further extended into a 3D supramolecular architecture by π–π interactions. Compound 6 exhibits a 3D binodal 4-connected framework with (4²6³8)₂ topology. Compound 7 furnishes a 3D (4,6)-connected framework with (4⁴6²)(4⁴6¹⁰8) topology. Compound 8 reveals a 3D 4-connected framework with 6⁶ topology. Compound 9 displays a 1D chain structure, which is further linked by hydrogen-bonding interactions to yield a 3D supramolecular architecture. Moreover, the diffuse reflectivity spectra of all the compounds, the solid state photoluminescence properties of compounds 4–5, and magnetic properties of compounds 1, 3, 6 and 7 were studied.