A series of bis(pyridyl)-bis(amide)-modulated metal-1,2-phenylenediacetate coordination polymers: construction and selective dye adsorption

Five new coordination polymers (CPs), namely, [Cu(3-bpcb)(1,2-pda)].2H(2)O(1), [Cu(4-bpah)(1,2-pda)(H2O)].H2O (2), [Ni-2(4-bpah)(2)(1,2-pda)(2)(mu(2)-H2O)] (3), [Cu-3(4-bpfp)(1,2-pda)(2)(mu(3)-OH)(2)] (4), [Co(4-bpfp)(0.5)(1,2-pda)(H2O)] (5), were prepared by hydrothermal reactions of metal(II) chloride with 1,2-H(2)pda (H(2)pda = 1,2-phenylenediacetic acid) in the presence of different bis(pyridyl)-bis(amide) ligands (3-bpcb = N, N'-bis(3pyridinecarboxamide)-1,4-benzene; 4-bpah = N, N'-bis(4-pyridinecarboxamide)-1,2-cyclohexane; and 4-bpfp = N, N'-bis(4-pyridylformyl) piperazine) and structurally characterized by single crystal X-ray diffraction, infrared spectroscopy (IR), elemental analysis, powder X-ray diffraction (PXRD) and thermogravimetric analysis (TGA). Complexes 1-3 show three different 2D layers with diverse (4(2).6(7).8)(4(2).6), (4(4).6(2)) and (4(2).6)(4(2).6(7).8) topological structures, respectively. Complex 4 exhibits a 3D polymeric framework, which presents a novel (3,4,8)-connected topology with the Schlafli symbol (3.4.5) 2(3(2).4(2).5(2).6(14).7(4).8(3).9)(3(2).6(3).7). Complex 5 displays a 3D network with 3,4-connected (4(2).6(3).8)(4(2).6) topology. The diverse arrangements of these complexes show the remarkable sensitivity of the metal(II)-H(2)pda system to the different bis(pyridyl)-bis(amide) ligands. In addition, the electrochemical properties of complexes 3-5 and the dye adsorption properties of the title complexes are also discussed.