Two 3D Cobalt(II) Metal-Organic Frameworks with Micropores for Selective Dye Adsorption.

Two porous coordination polymers, {[Co0.5(TBC)]·2DMF} n (1) and {[Co(TBC)Cl0.5(CH3OH)]·0.5Cl} n (2), were synthesized via the solvothermal reaction of cobalt(II) salts and 3,5-bis(1 H-1,2,4-triazol-1-yl)benzenecarboxylic acid. Single-crystal X-ray diffraction analyses exhibited that complex 1 contains rtl three-dimensional (3D) skeleton and one-dimensional channels with large apertures, while complex 2 displays a novel 2-nodal 3,6-linked 3D structure with a Schläfli sign of {4.82}2{46.89} and contains micropores. Meanwhile, compound 2 shows selective adsorption properties of anionic methyl orange in a water solution. The dye adsorption studies of 1 and 2 revealed that the porous character and charge properties of metal-organic frameworks are two important factors heavily influencing dye adsorption.

Terbium Triangle Bridged by a Triazole Nitronyl Nitroxide Radical with Single-Molecule-Magnet Behavior.

An unprecedented cyclic TbIII-radical cluster, [Tb3(hfac)6(4-Me-3-NITtrz)2(OH)3] (1), has been self-assembled from Tb(hfac)3·2H2O and 4-Me-3-NITtrz in the presence of Cu(hfac)2·2H2O. Alternating-current magnetic studies show that the Tb3 cluster displays a dual slow relaxation of magnetization behavior under a zero direct-current (dc) field and a single relaxation process under an induced dc field with an effective energy barrier of 14 K, representing the first triangle 2p-4f cluster with a slow magnetic relaxation property.

Lanthanide Tetranuclear Cage and Mononuclear Cocrystalline Nitronyl Nitroxide Complex with Single-Molecule-Magnet Behavior.

The first tetranuclear metallacage and mononuclear cocrystalline DyIII-radical complex was synthesized and characterized. The metallacage in [Dy4(hfac)8(IMPhThio)2(OH)4][Dy(hfac)3(NITPhThio)2] consists of Dy(hfac)2+ groups bridged by OH- and the IMPhThio radical. Field-induced single-molecule-magnet behavior was observed in the nitronyl nitroxide radical-bridged polynuclear complex.

[Removal Performance of Suspended Solid (SS) and Organic Compounds in the Pre-treatment of Actual Pharmaceutical Wastewater by Microbubble Ozonation].

Actual pharmaceutical wastewater was pretreated with ozone microbubbles and compared with the treatment processes of nitrogen microbubbles, ozone common bubbles, and nitrogen common bubbles. The removal process and performance of suspended solids (SS) and organic compounds were investigated. The results showed that ozone microbubble treatment with strong adsorption-flotation-oxidation effects could enhance SS removal significantly, and the corresponding SS removal efficiency reached 81.67% at 60 min. The SS particle size was reduced, and the negative charge on the SS surface was simultaneously changed into a positive charge. Microbubble ozonation with a strong·OH oxidation effect also significantly enhanced the degradation and removal of organic compounds. The removal efficiency of soluble COD (SCOD) reached 36.60% at 60 min, and the SCOD removal was accelerated after the SS removal. The removal efficiency of UV254 also reached 36.91%. The biodegradability was improved, and the biological toxicity was obviously eliminated. The analysis of three-dimensional fluorescence and GC-MS showed that the macromolecular organic compounds with complex structure could be oxidized and decomposed efficiently with microbubble ozonation, resulting in the aromatic reduction in organic compounds in wastewater. Therefore, microbubble ozonation could be considered as an efficient and feasible pretreatment method for high concentration and refractory pharmaceutical wastewater.

A Zn(ii) metal-organic framework based on bimetallic paddle wheels as a luminescence indicator for carcinogenic organic pollutants: phthalate esters.

Based on the multifunctional ligand 3-(1H-1,2,4-triazol-1-yl)isophthalic acid (H2TIA), a three-dimensional coordination polymer, namely {[Zn(TIA)]·DMA} n (Zn-1) was synthesized solvothermally. Single-crystal X-ray diffraction analyses confirmed that Zn-1 is a 3D framework composed of binuclear Zn2 paddle wheels with one-dimensional channels long the a direction. Further topological analyses revealed that MOF Zn-1 existed as a (3,6)-connected rtl binodal net {4·62}2{42·610·83}. Furthermore, the luminescence explorations indicate that complex Zn-1 is the first MOF for luminescent probing of phthalate esters (carcinogenic organic pollutants) with a high quenching-efficiency constant and low fluorescence-detection limit.

Slow relaxation of the magnetization observed in mononuclear Ln-radical compounds with D4d geometry configurations.

The combination of LnIII ions (GdIII, TbIII or DyIII) and a pyrazole nitronyl nitroxide radical results in three isomorphous complexes, namely, [Ln(hfac)3(NIT-Pyz)]2 (Ln = Gd(1), Tb(2), Dy(3); hfac = hexafluoroacetylacetone; NIT-Pyz = 2-{3-pyrazolyl}-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide). Single crystal X-ray diffraction studies revealed that all of them are composed of two crystallographically independent mononuclear systems, in which the central LnIII ions are coordinated by three hfac and one bidentate chelating NIT-Pyz radical. The central LnIII ions are all in square antiprism geometry (D4d) polyhedron configurations. Based on the spin Hamiltonian calculations, there exist antiferromagnetic couplings in the GdIII-NIT radical system in complex 1. Complexes 2 and 3 show frequency-dependent out-of-phase signals in a zero field indicating single-molecule magnetic behavior. Moreover, Tb's complex (2) shows a single thermal relaxation process with an energy barrier of 26 K. For Dy's complex (3), the Orbach and Raman processes both contribute to the magnetic relaxation behaviors.

Synthesis of a series of hetero-multi-spin Ln2Cu3 complexes based on a methyl-pyrazole nitronyl nitroxide radical with slow magnetic relaxation behaviors.

Multinuclear hetero-tri-spin complexes based on a methyl-pyrazole nitronyl nitroxide radical, namely, [Ln2Cu3(hfac)12(4-NIT-MePyz)4] (Ln = Gd(1), Tb(2), Dy(3); hfac = hexafluoroacetylacetone; 4-NIT-MePyz = 2-{4-(1-methyl)-pyrazolyl}-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) have been successfully obtained through a one-pot reaction of the radical ligand (4-NIT-MePyz) with Cu(hfac)2 and Ln(hfac)3. These 2p-3d-4f complexes exhibit five-nuclear structures with the sequence [Cu-Rad-Ln-Rad-Cu-Rad-Ln-Rad-Cu], in which each 4-NIT-MePyz radical acting as a bidentate bridging ligand is coordinated to one Ln(hfac)3 unit through one oxygen atom of the NO groups and to one Cu(hfac)2 unit with one nitrogen atom from the pyrazole ring. For complex 1, based on the spin Hamiltonian calculations and MAGPACK program, it is concluded that there exist ferromagnetic couplings between GdIII and NIT radicals, as well as between CuII and free radicals with J1 = 6.8(1) and J3 = 1.3(2) cm-1, respectively, and antiferromagnetic interactions between radical and radical with J2 = -2.8(5) cm-1. Complex 2 shows frequency-dependent out-of-phase signals under a zero or 2000 Oe dc field indicating single-molecule magnetic behavior.

A family of multi-spin rare-earth complexes based on a triazole nitronyl nitroxide radical: synthesis, structure and magnetic properties.

The combination of LnIII ions (GdIII, TbIII or DyIII) and a triazole nitronyl nitroxide radical (4-Me-3-NITtrz) as spin carriers results in two mononuclear and one binuclear compounds, namely, [Ln(hfac)3(4-Me-3-NITtrz)(H2O)] (Ln = Gd(1), Tb(2); hfac = hexafluoroacetylacetone; 4-Me-3-NITtrz = 2-[3-(4-methyl-l,2,4-triazolyl)]-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) and [Dy(hfac)2(4-Me-3-NITtrz)2][Dy(hfac)4]·CHCl3. Compounds 1 and 2 are isostructural and crystallize in the P1̄ space group, whereas compound 3 crystallizes in the P21/n space group. In 1 and 2, the central LnIII ions are nine-coordinated (LnNO8) in a distorted spherical capped square antiprism geometry (C 4v) finished by three bischelate hfac anions and one bidentate triazole radical and one aqua molecule. While 3 is a mixed-coordinated binuclear compound with Dy1 in a triangular dodecahedron (D 2d) coordination sphere and Dy2 in a biaugmented trigonal prism (C 2v) coordination sphere. Magnetic studies show that compound 2 exhibits field-induced single-molecule magnet (SMM) behavior.

Implantable porous gelatin microspheres sustained release of bFGF and improved its neuroprotective effect on rats after spinal cord injury.

In this study, porous gelatin microspheres (GMSs) were constructed to improve the neuroprotective effect of basic fibroblast growth factor (bFGF) on spinal cord injury. GMSs were prepared by a W/O emulsion template, followed by cross-linking, washing and drying. The particle sizes and surface porosity of the blank GMSs were carefully characterized by scan electronic microscopy. The blank GMSs have a mean particle size of 35µm and theirs surface was coarse and porous. bFGF was easily encapsulated inside the bulk GMSs through diffusion along the porous channel. 200µg of bFGF was completely encapsulated in 100mg of GMSs. The bFGF-loaded GMSs displayed a continuous drug release pattern without an obvious burst release over two weeks in vitro. Moreover, the therapeutic effects of bFGF-loaded GMSs were also evaluated in spinal cord injury rat model. After implantation of bFGF-loaded GMSs, the recovery of the motor function of SCI rats were evaluated by behavioral score and foot print experiment. The motor function of SCI rats treated with bFGF-loaded GMSs was more obvious than that treated with free bFGF solution (P<0.05). At the 28th days after treatment, rats were sacrificed and the injured spinal were removed for histopathological and apoptosis examination. Compared with treatment with free bFGF solution, treatment with bFGF-loaded GMSs resulted in a less necrosis, less infiltration of leukocytes, and a reduced the cavity ratio and less apoptotic cells in injured spinal(P<0.01), indicating its better therapeutic effect. Implantable porous GMSs may be a potential carrier to deliver bFGF for therapy of spinal cord injury.