Unsubstituted and substituted copper malonate coordination polymers with isomeric dipyridylamide ligands: Chain, layer, diamondoid, and self-penetrated topologies

Six dual-ligand divalent copper malonate coordination polymers have been prepared via solvent diffusion methods, and structurally characterized by single-crystal X-ray diffraction. The resulting dimensionality and topology depend crucially on the steric bulk of the malonate ligand and the nitrogen donor disposition within the dipyridylamide coligand. {[Cu(mal)(3-pina)(H2O)]center dot 2H(2)O}(n) (1, mal = malonate, 3-pina = 3-pyridylisonicotinamide) possesses a simple 1-D chain structure, while the isomeric 4-pyridylnicotinamide (4-pna) ligand afforded a two-fold interpenetrated (6,3) grid layer structure in {[Cu(mal) (4-pna)(H2O)]center dot 3H(2)O}(n) (2). Employing copper dimethylmalonate (dmmal) in the synthetic regime permitted synthesis of the (4,4) grid layered phase {[Cu-2(dmmal)(2)(4-pna)(2)(H2O)(3)]center dot 7H(2)O}(n) (3) and {[Cu-2(dmmal)(2)(3-pina)(2)]center dot 9.5H(2)O}(n) (4), which exhibited a three-fold interpenetrated diamondoid net with large water-filled incipient channels, built from [Cu-4(dmmal)(4)] tetranuclear clusters. {[Cu-2(Hdmmal)(2)(dmmal)(4-pina)(2)]center dot 0.5H(2)O}(n) (5, 4-pina = 4-pyridylisonicotinamide) manifested a unique 5-connected self-penetrated 3D network with 4(2)6(7)8 topology. {[Cu(emal)(4-pna)(H2O)]center dot 3H(2)O}(n) (6, emal = ethylmalonate) is another simple 1-D chain phase. Ferromagnetic coupling (J = 11(3) cm(-1)) was observed within the tetranuclear clusters in 4. Thermal properties of these materials are also presented. (C) 2016 Elsevier B.V. All rights reserved.