Zheng-Bo Han

Exceptionally Robust In-Based Metal-Organic Framework for Highly Efficient Carbon Dioxide Capture and Conversion.

An In-based metal-organic framework, with 1D nanotubular open channels, In2(OH)(btc)(Hbtc)0.4(L)0.6·3H2O (1), has been synthesized via an in situ ligand reaction, in which 1,2,4-H3btc is partially transformed into the L ligand. Compound 1 exhibits exceptional thermal and chemical stability, especially in water or acidic media. The activated 1 presents highly selective sorption of carbon dioxide (CO2) over dinitrogen. Interestingly, diffuse-reflectance infrared Fourier transform spectroscopy with a carbon monoxide probe molecule demonstrates that both Lewis and Brønsted acid sites are involved in compound 1. As a result, as a heterogeneous Lewis and Brønsted acid bifunctional catalyst, 1 possesses excellent activity and recyclability for chemical fixation of CO2 coupling with epoxides into cyclic carbonates under mild conditions. In addition, the mechanism for the CO2 cycloaddition reaction has also been discussed.

Robust Molecular Bowl-Based Metal–Organic Frameworks with Open Metal Sites: Size Modulation To Increase the Catalytic Activity

Herein, two stable lead(II) molecular-bowl-based metal-organic frameworks and their micro- and nanosized forms with open metal sites were presented. These materials could act as Lewis acid catalysts to cyanosilylation reaction. Moreover, the catalytic performances are size-dependent, with the catalyst with nanosized form being 1 order of magnitude more efficient than those with micro- and millisized forms.

Microporous Hexanuclear Ln(III) Cluster-Based Metal–Organic Frameworks: Color Tunability for Barcode Application and Selective Removal of Methylene Blue

Two hexanuclear Ln(III) cluster-based metal-organic frameworks (MOFs) (Ln = Tb or Eu) and a series of isomorphic bimetallic Ln(III)-MOFs have been synthesized by changing the ratio of Tb(III) and Eu(III) under solvothermal conditions. The excellent linear color tunability (from green to red) makes them suitable for barcode application. In addition, the anionic Ln(III)-MOFs exhibit superior uptake capacity toward methylene blue (MB+) by an ion-exchange process, and its reversible adsorption performance makes 1 suitable for removal of organic dye MB+. The as-prepared anionic hexanuclear Ln(III) cluster-based MOFs can serve as a multifunctional material for an optical and environmental area.

A dual-functional Cd(II)–organic-framework demonstrating selective sensing of Zn2+ and Fe3+ ions exclusively and size-selective catalysis towards cyanosilylation

A dual-functional complex with the formula Cd2(L)(DMF)2(H2O)2 (L = 2,3′,5,5′-biphenyl tetracarboxylic acid) has been successfully synthesized under solvothermal conditions and characterized by thermogravimetric analyses, IR spectroscopy, X-ray powder diffraction and single crystal X-ray diffraction. This material can selectively sense Zn2+ and Fe3+ ions over mixed metal ions through fluorescence enhancement and quenching, respectively. The cyanosilylation of aldehydes reaction studied used activated complex as a catalyst; the results showed that this complex with Lewis acid sites can act as a stable heterogeneous catalyst.

Three 3D coordination polymers based on [1,1′:4′,1′′-terphenyl]-2′,4,4′′,5′-tetracarboxylate demonstrating magnetic properties and selective sensing of Al3+/Fe3+over mixed ions

Three three-dimensional (3D) coordination polymers with the formulae [Cd(TPTC)0.5(H2O)2] ·DMA (1), [Co2(TPTC)(H2O)1.5(CH3OH)0.5] (2), and [Mn2(TPTC)(H2O)(DMA)]·DMA (3) (TPTC = [1,1′:4′,1′′-terphenyl]-2′,4,4′′,5′-tetracarboxylate acid) were solvothermally synthesized. They were characterized by thermogravimetric analyses, IR spectroscopy, X-ray powder diffraction, and single crystal X-ray diffraction. 1 features a 3D porous coordination polymer formed from Cd-carboxylate chains and the TPTC bridges. In 2 and 3, the uniform metal–carboxylate chains with triple bridges, (μ-EO-H2O)(μ-syn,syn-COO)2 and (μ-EO-H2O/DMA)(μ-syn,syn-COO)2 (EO = end-on), were extended by the TPTC arms. Complex 1 displayed strong fluorescent emission in the visible region. Interestingly, the emission intensities of 1 were increased upon the addition of Al3+ and quenched upon the addition of Fe3+, even in mixtures of ions. Thus, 1 can act as a useful material for sensing Fe3+ and Al3+ ions. The magnetic studies of 2 and 3 show that antiferromagnetic interactions between the Co(II) and Mn(II) centers exist.

Luminescent lanthanide–organic polyrotaxane framework as a turn-off sensor for nitrobenzene and Fe3+

Three isomorphous lanthanide–organic polyrotaxane frameworks [Ln(mtpc)1.5(DMA)(H2O)]·2H2O [Ln = Tb (1); Dy (2); Er (3)] were assembled and characterized. In 1, the mtpc ligand transfer absorbed energy to Tb3+ center to emit characteristic fluorescence. 1 can act as a fluorescent probe for selectively detecting nitrobenzene and iron(III) ions through luminescence quenching. Importantly, the detection limit of nitrobenzene is on the 15–150 ppm scale.

Anionic metal–organic framework for high-efficiency pollutant removal and selective sensing of Fe(III) ions

An anionic metal–organic framework, (DMA)2[Y9(μ3-OH)8(μ2-OH)3BTB6]n·(solv)x (DMA = dimethylamine cation and BTB = 1,3,5-benzene(tris)benzoate), (gea-MOF-1), is a novel rare earth (RE) nonanuclear MOF with an unusual gea topology. It could be used as an adsorbent material for efficiently removing the cationic dye MB+. This MOF can not only emit strong fluroescence in MeOH suspension, but also serves as a fluorescent probe for selectively detecting Fe3+ among other metal ions through luminescence emission quenching.

Synthesis, characterization, and DNA interaction of novel Pt(II) complexes and their cytotoxicity, apoptosis and molecular docking

The complexes [Pt{Ar(COOH)2}(OH)2] (1), [Pt{Ar(COOH)2}(OH)2]·H2O (2) have been synthesized and characterized by IR, 1H NMR, element analysis and single-crystal X-ray diffractometry. The interaction of the Pt(II) complexes with fish sperm DNA was explored by UV absorption, fluorescence spectroscopy and viscosity measurements. The results indicated that the complexes bind to FS-DNA in an intercalative mode with different binding affinities. The reaction of the complexes with N7, N3/N9 from guanine and adenine were investigated by 1H NMR. A gel electrophoretic assay demonstrated the ability of the Pt(II) complexes to cleave the pBR322 plasmid DNA. The docking methods were used to predict the DNA binding affinity of Pt(II) complexes by the resulting relative binding energy with DNA with −6.74 kcal mol−1 (complex 1) and −6.21 kcal mol−1 (complex 2). The cytotoxic activity of the complexes was tested against Hela cancer cell lines. The two complexes showed cytotoxic specificity and a significant cancer cell inhibitory rate. Complex 1 possessed the highest inhibition on viability of tested cells. Furthermore, the apoptotic tests indicated that the complexes had an apoptotic effect on HeLa cells.

A luminescent metal–organic framework for highly selective sensing of nitrobenzene and aniline

A stable nonanuclear rare earth carboxylate cluster based metal–organic framework, (DMA)2[Y9(μ3-OH)8(μ2-OH)3BTB6]n·(solv)x (gea-MOF-1) (DMA = dimethylamine cation and BTB = 1,3,5-benzene(tris)benzoate) can act as a fluorescent sensor for highly sensitive and selective detection of nitrobenzene and aniline through fluorescence quenching. More importantly, the detection limit of nitrobenzene is on the 5–60 ppm scale.

Two porous Co(II) bithiophenedicarboxylate metal–organic frameworks: from a self-interpenetrating framework to a two-fold interpenetrating α-Po topological network

Two new porous metal–organic frameworks with the formulas [Co(btdc)(bpp)(H2O)0.5]·8H2O (1) and Co2(btdc)2(bpe)2·19H2O (2) (H2btdc = 2,2′-bithiophene-5,5′-dicarboxylic acid, bpp = 1,3-di(4-pyridyl)propane, bpe = 1,2-bis(4-pyridinyl)ethane) have been synthesized under solvothermal conditions and characterized by single crystal X-ray diffraction analysis and powder X-ray diffraction, elemental analysis, IR, and thermogravimetric analysis (TGA). 1 features a three-dimensional (3D) self-interpenetrating framework which results from three-fold interpenetrating diamond network linked by the bpp ligands. 2 exhibits a three-dimensional two-fold interpenetrating pillar-layered framework with α-Po topology. The magnetic study of 1 shows that there exist antiferromagnetic interactions between the Co(II) centres.