A luminescent europium-organic framework with tubular channels based on the H4BTMIPA ligand (H4BTMIPA = 5,5'-methylenebis(2,4,6-trimethylisophthalic acid)) was assembled and characterized. The [H2N(CH3)2](+) ions as counterions are located in the channels. The cation exchange between [H2N(CH3)2](+) and metal ions resulted in complex that can selectively sense Fe(3+) and Al(3+) ions through fluorescence quenching and enhancement, respectively.
The current study describes the first barium-organic framework with permanent porosity, efficiently catalytic capacity, and highly selective luminescent sensing of DMSO molecule and metal ions. The single-crystal-to-single-crystal transformations (from complex 1 to complexes 2 and 3) were used to thermally generate coordinatively unsaturated metal sites (CUSs) as catalytically active sites (CASs). Complex 3 exhibits efficiently catalytic capacity for the cyanosilylation of aldehydes and ketones, and the cycloaddition of CO 2 and epoxides. To the best of our knowledge, complex 3 keeps a record among the MOF-based catalysts for the cyanosilylation of aldehydes and ketones. The generation of Ba 2+ CUSs with highly catalytic activity through SCSC fashion is responsible for the excellent property of 3, which is further confirmed by the theoretical calculation. Besides, complex 2 can highly sense DMSO molecule through fluorescence enhancement.
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Graphical AbstractThrough single-crystal-to-single-crystal transformation, highly active Ba 2+ open metal sites are achieved in a porous metal-organic framework, which exhibits efficiently catalytic capacity to the cyanosilylation of aldehydes and ketones and shows excellent fluorescent sensing of DMSO molecule and metal ions.
Through a pillar-ligand extension strategy, a rare breathing behavior in polycatenated 2D→3D nets has been achieved. Three variants exhibit interesting sorption properties that range from non-breathing to breathing behaviors, which is influenced by the angles between the pillars and the single honeycomb layers. The increase in pillar length does not lead to an increase in polycatenation multiplicity, which is controlled by the length of intralayer tripodal carboxylate. It also does not induce obviously expanded interlayer separations but occupies much more the free voids, and as a consequence, a smaller pore volume is obtained. This suggests that in 2D→3D polycatenated bilayer metal-organic frameworks, the porosity is not always enhanced by increasing the length of the interlayer pillars with the intralayer linker remaining unchanged.
Five metal−organic coordination complexes w i t h t h e f o r m u l a s oand {[Ni(L)(H 2 O) 2 ]•4H 2 O} n (5), (H 2 L OMe = 4,4′-(2,3,6,7-tetramethoxyanthracene-9,10diyl)dibenzoic acid) based on a new rigid dicarboxylate ligand were synthesized and structurally characterized. Structural analysis reveals that H 2 L OMe acts as multibidentate bridging linker to connect metal ions and possesses similar coordination modes with terephthalic acid. Complex 1 is a (4 4 )-sql layer incorporating bidentate-bridging H 2 L OMe and infinite Mn-(CO 2 ) 2 SBUs. Complexes 2 and 3 have similar 2D (3 6 )-hxl layer topology structure based on bidentate-chelating/bridging H 2 L OMe ligand and trinuclear hourglass SBUs. Complexes 4 and 5 are isostructural and possess 3D open frameworks based on infinite M-(μ 2 -H 2 O) chain. From the viewpoint of crystal structure diversity and comparison, our results further demonstrate that the coordination mode of metal ions and ligand are the vital elements in determining the final crystal structure. Moreover, thermal stabilities of 1−5 and temperature-dependent photoluminescence behaviors of 1 and 2 are discussed.
Two 3D noninterpenetrating porous metal-organic frameworks (PMOFs) [Cd3(L(1))2(DMA)2]·DMA [1, H3L(1) = tris(p-carboxylic acid)tridurylborane] and [Zn3(L(2))3(H2O)2]·5H2O·2EtOH [2, H2L(2) = 4,4'-((2,3,5,6-tetramethylphenyl)boranediyl)bis(2,3,5,6-tetramethylbenzoic acid)] were synthesized by employment of a C3-symmetric ligand (H3L(1)) to assembly with Cd(NO3)2 or Zn(NO3)2. Complex 1 exhibits a (3, 6)-connected topological network based on a Cd3 cluster and Y-shaped trinodal organic linker. Complex 2 shows a 6-connected topology, since in situ decarboxylic reaction of the initial H3L(1) occurred to generate a new ligand, H2L(2), which can be considered as a linear linker. Both 1 and 2 exhibit blue fluorescence. Significantly, complex 1 with larger channels is unstable upon the removal of guest molecules. In contrast, activated 2 exhibits higher stability and permanent porosity.
The 1-piece hydrophobic acrylic foldable PC IOL was not suitable for sulcus transscleral fixation because of a high incidence of PDS and pigmentary glaucoma after surgery in a Chinese population.
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