Two copper(II) metal–organic networks derived from bis-pyridyl-bis-amide ligands and aromatic polycarboxylates: a 2-D layered structure and a 4-connected trinodal 3-D topology.

Two metal–organic coordination polymers, [Cu3(4-bpcb)2(1,2,4-btc)2(H2O)2] (1) and [Cu3(3-bpcb)3(btec)1.5] (2), have been synthesized from hydrothermal reaction of copper chloride with mixed ligands [4-bpcb = N,N′-bis(4-pyridinecarboxamide)-1,4-benzene, 3-bpcb = N,N′-bis(3-pyridinecarboxamide)-1,4-benzene, 1,2,4-H3btc = 1,2,4-benzenetricarboxylic acid, and H4btec = 1,2,4,5-benzenetetracarboxylic acid]. X-ray diffraction analysis reveals that1exhibits a 2-D layer structure and2possesses a three-dimensional (3-D) network. In1and2, CuIIions are connected by bridging 1,2,4-btc or btec to form 2-D polymeric layers. Cu-1,2,4-btc layer does not propagate into a 3-D coordination framework in1due to 4-bpcb showing monodentate coordination (via ligation of only one pyridyl nitrogen). In2, Cu-btec 2-D layers are further extended into a 3-D network with (64.82)3topology by 3-bpcb ligand inμ2-bridging coordination (via ligation of two pyridyl nitrogens). The different structures of the two complexes illustrate the influence of different polycarboxylates and N-donor positions of organic ligands on the formation of such coordination architectures. Moreover, the thermal properties and electrochemical properties of the copper complexes bulk-modified carbon paste electrodes have been studied. [ABSTRACT FROM AUTHOR]