Zhuo-Wei Wang

Ligand Symmetry Modulation for Designing a Mesoporous Metal–Organic Framework: Dual Reactivity to Transition and Lanthanide Metals for Enhanced Functionalization

A promising alternative strategy for designing mesoporous metal-organic frameworks (MOFs) has been proposed, by modifying the symmetry rather than expanding the length of organic linkers. By means of this approach, a unique MOF material based on the target [Zn8(ad)4] (ad = adeninate) clusters and C3-symmetric organic linkers can be obtained, with trigonal microporous (ca., 0.8 nm) and hexagonal mesoporous (ca., 3.0 nm) 1D channels. Moreover, the resulting 446-MOF shows distinct reactivity to transition and lanthanide metal ions. Significantly, the transmetalation of Co(II) or Ni(II) on the Zn(II) centers in 446-MOF can enhance the sorption capacities of CO2 and CH4 (16-21%), whereas the impregnation of Eu(III) and Tb(III) in the channels of 446-MOF will result in adjustable light-emitting behaviors.

A Versatile AlIII-Based Metal–Organic Framework with High Physicochemical Stability

A unique Al(III) -based metal-organic framework (467-MOF) with two types of square channels has been designed and synthesized by using a flexible tricarboxylate ligand under solvothermal conditions. 467-MOF exhibits superior thermal and chemical stability and, moreover, shows high CO2 sorption selectivity over H2 , with a selectivity, based on the ideal adsorbed solution theory (IAST) of approximately 45 at 273 or 293 K. Furthermore, its solvent-dependent photoluminescence makes it an applicable sensor in the detection of nitrobenzene explosives through fluorescence quenching.

Metal–Organic Framework Supported on Processable Polymer Matrix by In Situ Copolymerization for Enhanced Iron(III) Detection

Metal-organic frameworks (MOFs) represent a promising class of porous materials. However, MOFs show poor processability that impedes their full potential in applications. This work develops a composite strategy to skillfully load MOFs on a polymer plate to afford processability for these powder materials. A predesigned mesoporous MOF with active -NH2 groups around the pore walls was prepared and its copolymerization with the -NCO groups of macromonomers (polyurethane acrylate) could be facilely induced by an initiator under mild conditions. Notably, the target MOF-polymer composite is transparent, elastic, and shows enhanced Fe3+ detection compared with that of the individual MOF functional component. This result can be ascribed to the synergistic effect of the composite with newly formed chemical bonds between the MOF particle and polymer matrix.

Iron oxide@mesoporous carbon architectures derived from an Fe(II)-based metal organic framework for highly sensitive oxytetracycline determination

A series of nanocomposites comprised of iron oxide and mesoporous carbon (denoted as Fe3O4@mC) were derived from an Fe(II)-based metal–organic framework (525-MOF) by calcining at different temperatures. The advantages of chemical functionality, strong bioaffinity, and high stability of the Fe3O4@mC can be combined with the high specific surface area of 525-MOF leading to the formation of Fe3O4@mC nanocomposites as a scaffold for oxytetracycline (OTC) aptamer strands. The use of Fe3O4@mC nanocomposites reveals high OTC detection efficiency. The nanocomposite calcined at 900 °C (denoted as Fe3O4@mC900) is found to be the best candidate toward high-sensitivity and high-selectivity detection of OTC because of its excellent functionality, nanostructural properties, and high electrochemical performance. Accordingly, the Fe3O4@mC900-based electrochemical aptasensor displays high sensitivity with a low detection limit of 0.027 pg mL−1 within a broad linear range of OTC concentration from 0.005 to 1.0 ng mL−1. The aptasensor also exhibits high selectivity, reproducibility, stability, regenerability, and applicability in milk samples. All of these results indicate that the Fe3O4@mC nanocomposites that originated from 525-MOF can be applied in the fields of trace and fast antibiotic determination.

Two 3-D Cd II /Zn II complexes based on mixed 1,1-cyclobutanedicarboxylate and 4,4′-bipyridine ligands

Two new 3-D complexes, [M(L)(4bpy)0.5(H2O)]∞ [M = Cd (1) and = Zn (2)], based on mixed 1,1-cyclobutanedicarboxylic acid (H2L) and 4,4′-bipyridine (4bpy) have been synthesized; 1 and 2 feature (3,4)-connected (63)(65.8) topological networks consisting of pillared 2-D [M(L)(H2O)]∞ layered motifs. Complexes 1 and 2 are photoluminescent materials. Graphical abstract Reported here are two new CdII/ZnII complexes exhibiting 3-D (3,4)-connected (63)(65.8) topological network.

Co/Fe-bimetallic organic framework-derived carbon-incorporated cobalt–ferric mixed metal phosphide as a highly efficient photocatalyst under visible light

A new bimetallic Co/Fe-MOF was synthesized and phosphatized to produce a visible-light-active Co/Fe binary metal phosphide embedded in a mesoporous carbon matrix (denoted by CoP/Fe2P@mC). The results of X-ray diffraction and photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy reveal the formation of CoP and Fe2P nanoparticles together with the Co and Fe metallic state. Combining the high electron-hole separation rate of Fe2P@mC, fast electron transfer of CoP@mC, and the strong adsorption of mesoporous carbon, the as-prepared CoP/Fe2P@mC catalyst exhibits substantially enhanced photocatalytic activity toward rhodamine B (RhB) degradation under visible light irradiation. Visible light harvesting efficiency is enhanced by the suitable bandgap structure of the CoP/Fe2P@mC photocatalyst. Moreover, the possible photocatalytic mechanism of CoP/Fe2P@mC toward RhB degradation was proposed on the basis of radical trapping and electron spin resonance results. This finding illustrates a potential utilization of bimetallic MOF-derived metal phosphide as a photocatalyst to remove dye pollutants in the environment.

Distinct 3D CdII Coordination Polymers with 1,2-Naphthalenedicarboxylate Regulated by Dipyridyl Co-Ligands with Different Spacers

Two distinct three-dimensional (3D) CdII coordination polymers with 1,2-naphthalenedicarboxylate (ndc2–) and dipyridyl co-ligands have been synthesized under hydrothermal conditions. Interestingly, the slight difference in the two 4,4′-dipyridyl building blocks, namely, 1,2-bi(4-pyridyl)ethane (bpp) and 1,2-bi(4-pyridyl)ethene (bpe) with C–C or C=C spacers, results in the significant structural divergence of the resultant coordination polymers. Structural analysis reveals that complexes [Cd(ndc)(bpp)(H2O)]n (1) and {[Cd5(ndc)4(bpe)2(OH)2](H2O)1.5}n (2) are constructed by discrete metal–carboxylate dimeric units and metal–carboxylate chains, respectively, which are further extended by bpp or bpe linkers to form the inclined interpenetrated two-dimensional (2D)→3D network for 1 and the 3D porous framework for 2. This result reveals that the flexibility of auxiliary ligands plays an important role in the structural assemblies of coordination networks. The thermal and luminescence properties of both complexes were also investigated in solid state.

Three ZnII Coordination Polymers Based on 1,2-Naphthalenedicarboxylate and Different 4,4′-Bipyridyl-like Bridging Co-ligands: Structural Regulation and Properties

Three new ZnII coordination polymers, namely [Zn(ndc)]n (1), {[Zn(ndc)(bpe)]·1.25H2O}n (2), and {[Zn(ndc)(bpee)]·1.25H2O}n (3), were prepared based on in situ reaction of 1,2-naphthalenedicarboxylic anhydride (ndca) with two different 4,4′-bipyridyl-like bridging co-ligands, bpe and bpee (ndc = 1,2-naphthalenedicarboxylate, bpe = 1,2-bis(4-pyridyl)ethane, and bpee = trans-1,2-bis(4-pyridyl)ethylene). In 1, the ZnII and ndc ligands are directly involved in the polymeric frameworks, forming a 2D (43.63) layered network. Complexes 2 and 3 similarly consist of Zn2(ndc)2 binuclear units that are linked by bpe and bpee ligands, respectively, into a 2D (44.62) sheet. However, further analysis indicates that 2 and 3 feature the similar 2-fold interpenetrating structure linked via hydrogen bonding interactions for 2 and aromatic stacking interactions for 3. In addition, the resultant 2D→3D supramolecular frameworks of 2 and 3 are both constructed via aromatic stacking interactions. Also, the fluorescent and thermal properties of the complexes were investigated.

A Novel (3,4,9)-Connected 3D Metal–Organic Framework Based on the Non-Planar Tricarboxyl Tecton and Zn5O4-Cluster SBU

Combination of a non-planar tripodal ligand 3,4-bi(4-carboxyphenyl)-benzoic acid (H3L) and Zn5O4-cluster secondary building units affords a highly connected three-dimensional metal–organic framework, {[Zn5(μ3-OH)3(μ2-OH)L2(H2O)2](H2O)2}n (1), which exhibits an unusual (3,4,9)-connected (42.5)(3.43.52)(32.45.511.613.73.82) topological net. The thermal stability and solid luminescence of the crystalline material have also been investigated.