One-Dimensional Coordination Polymers of Cobalt with 4,4'-Bipyridine: Syntheses and Structures

In situ time-resolved monitoring of mixed-ligand metal–organic framework mechanosynthesis

The mechanism of mixed-ligand metal–organic framework (MOF) formation, and the possible role of intermediate single-ligand metal complexes during mechanosynthesis, are explored for the first time.

Magnetic cobalt-embedded carbon nitride composite derived from one-dimensional coordination polymer as an efficient catalyst for activating oxone to degrade methyltheobromine in water

As methyltheobromine (MTB) has been increasingly detected in wastewater, it would be necessary to develop more intensive and effective approaches to remove MTB. As Co species immobilized on carbonaceous materials appears as a promising catalyst, doping carbon with nitrogen has been also validated to significantly enhance catalytic activities for Oxone activation. Therefore, it is desired to develop a composite of immobilizing Co species on N-doped carbonaceous supports for activating Oxone to degrade MTB. Unfortunately, very few studies have demonstrated such composites for activating Oxone to degrade MTB as this type of composites are conventionally prepared via complex procedures. Alternatively, this study aims to develop such a composite conveniently by using a cobaltic coordination polymer (CP) as a precursor. Specifically Co²⁺ and 4,4-bipyridine (BIPY) are selected for formulating a special one-dimensional CP, which is then carbonized to convert Co to Co nanoparticles (NPs) and transform BIPY to carbon nitride (CN) matrices. Because of 1-D coordinated structure of CoBIPY, the resulting magnetic Co NPs are well-distributed and protected within CN to form a magnetic Co-embedded carbon nitride composite (MCoCN). In comparison to pristine CN and Co₃O_4, MCoCN exhibits much higher catalytic activities to activate Oxone for degrading MTB completely within 7 min. MCoCN also shows a much lower activation energy of 24.6 kJ/mol than other reported catalysts for activating Oxone to degrade MTB. The findings of this study validate that the 1-D coordination polymer of CoBIPY is a useful precursor to prepare MCoCN for effectively activating Oxone to degrade MTB.

Nanoscale coordination polymers obtained in ultrasmall liquid droplets on solid surfaces and its comparison to different synthetic volume scales

Confined synthesis and comparative study of a coordination polymer at different volume scales, from the macroscopic to the femtolitre scale.

Constructing various metal–organic frameworks by mixed pyridine–acylamide and carboxylate ligands: ring-like or helical building blocks

To some extent, this work has demonstrated the coordination affinity of the L ligand and gives us some understanding of how to direct the next syntheses of L-based compounds.

The double-stranded ladder-like structure of poly[[bis(μ2-acetato-κ(2)O:O')bis(acetato-κO)bis(μ-4,4'-bipyridine-κ(2)N:N')dicopper(II)] 4-nitrophenol disolvate tetrahydrate]

The reaction of 4,4'-bipyridine with copper acetate in the presence of 4-nitrophenol led to the formation of the title compound, {[Cu(CH3COO)2(C10H8N2)]·C6H5NO3·2H2O}n. The complex forms a double-stranded ladder-like coordination polymer extending along the b axis. The double-stranded polymers are separated by 4-nitrophenol and water solvent molecules. The two Cu(II) centres of the centrosymmetric Cu2O2 ladder rungs have square-pyramidal coordination environments, which are formed by two acetate O atoms and two 4,4'-bipyridine N atoms in the basal plane and another acetate O atom at the apex. The ladder-like double strands are separated from each other by one unit-cell length along the c axis, and are connected by the water and 4-nitrophenol molecules through a series of O-H···O and C-H···O hydrogen-bonding interactions and two unique intermolecular π-π interactions.

Poly[diaqua-bis-(μ-4,4'-bipyridine-κ(2) N:N')bis-(ethane-1,2-diol-κO)bis(μ-sulfato-κ(2) O:O')dicobalt(II)]

In the title compound, [Co₂(SO₄)₂(C₁₀H₈N₂)₂(C₂H₆O₂)₂(H₂O)₂]_n, there are two crystallographically independent Co^II ions, each of which lies on a twofold rotation axis and has a slightly distorted octa­hedral environment. One Co^II ion is coordinated by two N atoms from two bridging 4,4′-bipyridine (4,4′-bipy) ligands, two O atoms from two sulfate ions and two O atoms from aqua ligands. The second Co^II ion is similar but with ethane-1,2-diol ligands in place of water mol­ecules. The sulfate anions act as bridging ligands to link two adjacent Co^II ions together, leading to the formation of linear ⋯Co1Co2Co1Co2⋯chains along the a axis. Adjacent chains are further bridged by 4,4′-bipy ligands, which are also located on the twofold rotation axis, resulting in a two-dimensional layered polymer extending parallel to (001). In the crystal, the layers are linked by extensive O—H⋯O hydrogen-bonding inter­actions involving the O atoms of the water mol­ecules and ethane-1,2-diol mol­ecules, resulting in a three-dimensional supra­molecular network.

A novel one-dimensional Co(II) coordination polymer: catena-poly[[hexaaquacobalt(II)] [[diaquabis(sulfato-κO)cobalt(II)]-μ-4,4'-bipyridine-κ2N:N'] [[triaqua(sulfato-κO)cobalt(II)]-μ-4,4'-bipyridine-κ2N:N']]

The title compound, {[Co(H(2)O)(6)][Co(SO(4))(C(10)H(8)N(2))(H(2)O)(3)][Co(SO(4))(2)(C(10)H(8)N(2))(H(2)O)(2)]}(n), contains three crystallographically unique Co(II) centres, all of which are in six-coordinated environments. One Co(II) centre is coordinated by two bridging 4,4'-bipyridine (4,4'-bipy) ligands, one sulfate ion and three aqua ligands. The second Co(II) centre is surrounded by two N atoms of two 4,4'-bipy ligands and four O atoms, i.e. two O atoms from two monodentate sulfate ions and two from water molecules. The third Co(II) centre forms part of a hexaaquacobalt(II) ion. In the crystal structure, there are two different one-dimensional chains, one being anionic and the other neutral, and adjacent chains are arranged in a cross-like fashion around the mid-point of the 4,4'-bipy ligands. The structure features O-H···O hydrogen-bonding interactions between sulfate anions and water molecules, resulting in a three-dimensional supramolecular network.

Highly selective and sensitive visualizable detection of Hg2+ based on anti-aggregation of gold nanoparticles

For the widely used gold nanoparticles (AuNPs)-based colorimetric probes, AuNPs generally change from dispersion to aggregation state accompanying with corresponding color turning from red to blue. Although colorimetric probes based on the anti-aggregation of AuNPs show exceptional selectivity and sensitivity, few examples have been reported in literature. A facile but highly sensitive and selective colorimetric probe based on the anti-aggregation of AuNPs transferred from the deactivation of aggregation agent 4,4'-dipyridyl by Hg(2+) was developed in this work. This reported probe is suitable for real-time detection of Hg(2+) in water with a detection limit of 3.0 ppb for Hg(2+), and exhibits a selectivity toward Hg(2+) by two orders of magnitude over other metal ions. The dynamic range of this probe can be conveniently tuned by adjusting the amount of 4,4'-dipyridyl used.

Synthesis, Structure and Photoluminescence of [N-ethyl-4,4′-bipyridinium][CdBr4] with N-ethyl-4,4′-bipyridinium Generated in situ

A new viologen(4,4′-bipyridinium)-based complex [ N-ethyl-4,4′-bipyridinium][CdBr4], in which N-ethyl-4,4′-bipyri-dinium ( EQ2+) has been generated in situ, has been synthesised via hydrothermal reaction and structurally characterised by single-crystal X-ray diffraction. [ N-ethyl-4,4′-bipyridinium][CdBr4] features an isolated structure, based on an N-ethyl-4,4′-bipyridinium moiety and a cadmium atom terminally bound by four bromine atoms. Photoluminescence investigation reveals a broad and intense emission in blue region, which may originated from π → π* charge-transfer interaction of the N-ethyl-4,4′-bipyridinium moiety.

Synthesis, structure, properties and a theoretical study of [ZnCl2(4,4'-bipy)]n

The compound [ZnCl2(4,4'-bipy)] n, has been synthesised via hydrothermal reaction and structurally characterised. It crystallises in the space group Cc of the monoclinic system: a = 15.883(5), b = 25.656(5), c = 14.642(6) Å, β = 110.321(4)°, V = 5595(3) Å3, C10H8Cl2N2Zn, M r= 292.45 g mol−1, D c= 1.736 g cm−3, S = 1.003, μ(Mo Kα) = 2.636 mm−1, F(000) = 2920, R = 0.0471 and wR = 0.0946. The complex has a one-dimensional zigzag chain-like structure. Photoluminescent investigation reveals that it displays a strong emission in the purple region and molecular orbital (MO) calculation indicates that the emission originates from the ligand-to-ligand charge-transfer (LLCT) transition.