Chuang Xu

The design and construction of a series of metal–organic coordination polymers based on two isomeric semi-rigid bis-pyridyl-bis-amide ligands and three aromatic polycarboxylates

A series of metal–organic coordination polymers, namely, {[Cu3(4-bpah)4(1,3,5-BTC)2]·8H2O}n (1), {[Cu3(4-bpah)3(1,2-BDC)3(H2O)2]·4H2O}n (2), {[Cu(4-bpah)(1,3-BDC)(H2O)]}n (3), {[Co(4-bpah)(1,3-BDC)(H2O)]}n (4), {[Ni(4-bpah)(1,3-BDC)(H2O)]}n (5), {[Zn(4-bpah)(1,3-BDC)(H2O)]}n (6), {[Cd(4-bpah)(1,3-BDC)]}n (7), {[Cd(3-bpah)(1,3-BDC)]·H2O}n (8), {[Cu2(3-bpah)(1,3-BDC)2]·H2O}n (9), where 4-bpah = N,N′-bis(4-pyridinecarboxamide)-1,2-cyclohexane, 3-bpah = N,N′-bis(3-pyridinecarboxamide)-1,2-cyclohexane, 1,3,5-H3BTC = 1,3,5-benzenetricarboxylic acid, 1,2-H2BDC = 1,2-benzenedicarboxylic acid, 1,3-H2BDC = 1,3-benzenedicarboxylic acid, have been synthesized under hydrothermal conditions. The structures of 1–9 have been determined by single crystal X-ray diffraction analyses and further characterized by infrared spectroscopy (IR), elemental analyses, powder X-ray diffraction (PXRD), and thermogravimetric analyses (TGA). Complex 1 displays a 2D (42·83·10)(43·62·8)4(4)2 topological network. Complex 2 shows a 2D (3·4·5·62·7)2(3·42·52·7) topological framework that contains tri-flexural and left-hand helix chains. Complexes 3–6 reveal a similar 2D sql network with (44·62) topology. Complexes 7 and 8 show two different 2D double-layer structures with (42·6)(43·6·84·102)(4) and (42·6·86·12)(42·6)(8) topology, respectively. Complex 9 exhibits a new 3D 3-nodal topology with the Schlafli symbol (4·62)2(42·64)2(42·68·82·103). The successful construction of complexes 1–9 implies that using semi-rigid bis-pyridyl-bis-amide ligands can obtain various architectures with small voids. The effect of the isomeric semi-rigid bis-pyridyl-bis-amide ligands and the three aromatic polycarboxylates, as well as the central metal ions on the formation and structures of the title coordination polymers have been discussed. The fluorescent and photocatalytic properties of complexes 1–9 have also been investigated.

Two novel octamolybdate-based frameworks decorated by flexible bis-pyridyl-bis-amide ligands with different spacer lengths

Two octamolybdate hybrid complexes based on flexible bis-pyridyl-bis-amide ligands with different spacer lengths, namely, {[Cu(L1)(β-Mo8O26)0.5(H2O)2]·H2O}n (1), [Cu(L2)(β-Mo8O26)0.5(H2O)] (2) (L1 = N,N′-bis(3-pyridinecarboxamide)-1,2-ethane, L2 = N,N′-bis(3-pyridinecarboxamide)-1,6-hexane), have been successfully synthesized. Crystal structure analysis reveals that 1 is a two-dimensional (2D) network constructed from [Cu-L1]n2n+ chains and [β-Mo8O26]n4n− anions, displaying a 4-connected framework with 32·62·72 topology. Compound 2 consists of double one-dimensional (1D) meso-helical chains and 1D inorganic chains to generate a three-dimensional (3D) framework with a (4,4)-connected (4·64·8)2(42·62·82) topology. The title compounds represent the first examples of introducing a flexible bis-pyridyl-bis-amide ligand into the isopolymolybdates system. In addition, the electrochemical behavior of 1, luminescent properties and photocatalytic activities of the title compounds have been investigated.

Role of aromatic dicarboxylates in the structural diversity of cobalt(II) and copper(II) coordination polymers containing a flexible N,N′-di(3-pyridyl)octanediamide ligand

Six new transition metal coordination polymers, namely, [Co(1,2-BDC)(L)1.5(H2O)] (1), [Co(1,3-BDC)(L)(H2O)2]·H2O (2) [Co(5-AIP)(L)0.5(H2O)]·2H2O (3), [Cu(1,2-BDC)(L)] (4), [Cu(1,3-BDC)(L)(H2O)]·3H2O (5), and [Cu2(5-AIP)2(L)2(H2O)]·6H2O (6) (L = N,N′-di(3-pyridyl)octanediamide, 1,2-H2BDC = 1,2-benzenedicarboxylic acid, 1,3-H2BDC = 1,3-benzenedicarboxylic acid, 5-H2AIP = 5-aminoisophthalic acid), have been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction. In compound 1, the adjacent CoII ions are connected by L ligands to form a 1D chain with an alternating arrangement of L ligands and Co2L2 dinuclear loops. The 1,2-BDC anions coordinate with one CoII ion in a bis(monodentate) chelate mode. Complex 2 shows a 2D (44) grid network with the sql topology, which consists of the 1D zigzag [Co–L]n chain and 1D linear [Co-1,3-BDC]n chain. When 5-H2AIP is used in compound 3, an interesting 2D terraced-type layer based on 1D [Co-5-AIP]2n ladder-like chains and μ2-bridging L ligands with 3,4-connected {62.10}{6} topology is formed. Under the similar conditions to compound 1, except that the cobalt(II) salt is replaced by a copper(II) salt, a 2D wave-like network 4 with 2,4-connected {64.8.10}{6} topology is obtained. Compound 5 displays a 3D coordination polymeric architecture based on 1D [Cu-1,3-BDC]n chains and [Cu–L]n chains, which represents an intriguing 3-fold interpenetrating framework with CdSO4-type topology. When 1,3-BDC is replaced by 5-AIP, another 3-fold interpenetrating 3D CdSO4-type coordination framework for compound 6 is obtained, which is constructed from three types of 1D chains: [La–Cu–Lc]n chain, [Lb–Cu–Lb]n chain and [Cu-5-AIP]n chain. The adjacent 1D chains for 1 and 2D layers for compounds 2, 3 and 4 are further extended by hydrogen bonding interactions to 3D supramolecular frameworks. The effect of dicarboxylates and central metals on the structures of the title complexes has been discussed. Furthermore, the electrochemical behaviors and solid state fluorescent properties for compounds 1–6 are investigated.

A novel polyoxometalate templated microporous metal–organic framework with electrochemical properties

A novel Wells–Dawson polyoxometalate-templated 3D microporous metal–organic framework (MOF), namely, H6[Cu3(H2O)6(P2W18O62)2(3-dpye)6]·28H2O (1) (3-dpye = N,N′-bis(3-pyridinecarboxamide)-1,2-ethane), was hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, IR spectra, powder X-ray diffraction (PXRD) and thermogravimetric analyses (TGA). Each Cu(II) ion acts as a four-connected node linking four 3-dpye ligands to construct a 3D microporous host MOF containing left-handed helical chains, in which the P2W18O626− anions reside. 1 represents the first example of 3D MOFs with an 86 uniform net containing non-coordinating Wells–Dawson anions. The electrochemical properties have been investigated in detail.

A twofold interpenetrating 3D Keggin-based Ag(I) complex based on a flexible bis-pyridyl-bis-amide

A Keggin-type polyoxometalate (POM)-based complex, [Ag5(L)3 (H2O)2]·6H2O (1) (L = N,N′-bis(3-pyridinecarboxamide)-1,2-ethane), has been hydrothermally synthesized. Compound 1 shows a 3D + 3D interpenetrating network with a (3,4,4,4)-connected (4 × 62)2(42 × 62 × 82)(65 × 8)2 topology, and it represents the first example of interpenetrating POM-based complex based on flexible bis-pyridyl-bis-amide ligands. Moreover, the electrochemical behavior and luminescence of 1 have been investigated.

The Role of the Coordination Modes of a Flexible Bis(pyridylamide) Ligand in the Topology of 2D Copper(II) Complexes

Two new two-dimensional copper(II) coordination polymers, [Cu(L)(BDC)]_H2O (1) and [Cu2(L)0:5(SIP)(OH)(H2O)] 2H2O (2) [L=N;N0-bis(3-pyridylamide)-1,6-hexane, H2BDC=1,3- benzenedicarboxylic acid, H3SIP=5-sulfoisophthalic acid (3,5-dicarboxybenzenesulfonic acid)], have been synthesized hydrothermally by self-assembly of the flexible bis-pyridyl-bis-amide ligand L and the aromatic polycarboxylate ligands H2BDC or H3SIP. X-Ray diffraction analysis reveals that complex 1 displays a metal-organic coordination layer with a binodal (3,5)-connected {42.67.8}{42.6} topology, in which the L ligands adopt a m2-bridging mode (via ligation of the pyridyl nitrogen atoms). Complex 2 also exhibits a layered network based on tetranuclear copper clusters [Cu4(μ3-OH)2(H2O)2(O2C-)4], L ligands and SIP anions, showing a binodal (4,8)-connected network with {414.610.84}{44.62} topology, in which the L ligands adopt a μ6-bridging coordination mode (via ligation of the pyridyl nitrogen and carbonyl oxygen atoms). Adjacent layers in 1 and 2 are further linked by hydrogen bonding interactions to form three-dimensional supramolecular frameworks. The electrochemical behavior of the two complexes in bulk-modified carbon paste electrodes has been investigated Graphical Abstract The Role of the Coordination Modes of a Flexible Bis(pyridylamide) Ligand in the Topology of 2D Copper(II) Complexes

Syntheses, Structures and Electrochemical Properties of Two New Copper(II) Complexes Based on Isomeric Bis(pyridylformyl)piperazine Ligands and Rigid=Flexible Organic Dicarboxylates

Two new copper(II) complexes, [Cu2(3-bpfp)(2,6-PDA)2(H2O)2] (1) and [Cu(4-bpfp)0:5 (glu)]·H2O (2), have been hydrothermally synthesized by self-assembly of isomeric bis(pyridylformyl)piperazine ligands [3-bpfp=bis(3-pyridylformyl)piperazine, 4-bpfp=bis(4- pyridylformyl)piperazine], rigid pyridine-2,6-dicarboxylic acid (2,6-H2PDA) or flexible glutaric acid (H2glu), and copper(II) chloride. Single-crystal X-ray diffraction analysis reveals that two adjacent CuII ions are connected by the 3-bpfp ligand to build a dinuclear unit in complex 1, in which 2,6-PDA serves as a terminal chelating ligand. Adjacent dinuclear units are further linked by hydrogen bonding and π-π stacking interactions to form a three-dimensional (3D) supramolecular network. Complex 2 is a 3D coordination polymeric framework based on a layer polymer [Cu(glu)]n and bridging 4-bpfp ligands with 6-connected (44.610.8) topology. In 1 and 2, the ligands 3-bpfp and 4-bpfp adopt a μ2-bridging coordination mode (via ligation of pyridyl nitrogen atoms). The thermal stability and the electrochemical properties of the title complexes have been studied. Graphical Abstract Syntheses, Structures and Electrochemical Properties of Two New Copper(II) Complexes Based on Isomeric Bis(pyridylformyl)piperazine Ligands and Rigid=Flexible Organic Dicarboxylates

CCDC 886120: Experimental Crystal Structure Determination

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