Hydrothermal Syntheses, Architectures and Magnetic Properties of Six Novel MnII Coordination Polymers with Mixed Ligands

Six novel manganese(II) coordination polymers, namely [Mn(oba)(4,4′-bpy)]n·n(4,4′-bpy) (1), [Mn(oba)(phen)(H2O)]n (2), [Mn2(oba)2(2,2′-bpy)2(H2O)2]n·nH2oba (3), [Mn2(cca)2(4,4′-bpy)2]n·2n(4,4′-bpy) (4), [Mn(cca)(phen)]n (5) and [Mn(cca)(2,2′-bpy)]n·0.25nH2O (6) [H2oba = 4,4′-oxybis(benzoic acid); 4,4′-bpy = 4,4′-bipyridine; phen = 1,10-phenanthroline; 2,2′-bpy = 2,2′-bipyridine; H2cca = p-carboxycinnamic acid] have been synthesised under hydrothermal conditions. Complexes 1 and 4 possess 3D microporous metal-organic frameworks with free 4,4′-bpy ligands in the channels. The MnII ions in complex 2 are bridged into 1D infinite double-chain structures, and those in complex 3 are bridged into 1D zigzag chains. Hydrogen bonds cause the formation of 3D supramolecular networks for complexes 2 and 3. Complex 5 is a complicated 3D metal-organic framework, and the MnII ions in complex 6 are linked into 2D layers with cavities; interpenetration of these 2D layers results in the formation of a 3D supramolecular network. Magnetic susceptibility measurements indicate that complex 2 displays a weak ferromagnetic interaction between the MnII ions with the following parameters: J = 0.462(3) cm–1, g = 2.0387(6), zJ′ =–0.0062(3) cm–1 and R = 8.0 × 10–6. Complex 4 shows antiferromagnetic coupling between the MnII ions with J =–0.718(4) cm–1, g = 1.986(4) and R = 2.3 × 10–4. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)