The dehydrogenative cross-coupling reaction is the premier route for synthesizing important 4-quinazolinone drugs. However, it usually requires high reaction temperature and long reaction time, and the yield of the final product is low. Here two stable and photosensitive covalent-organic frameworks (COFs), TAPP-An and TAPP-Cu-An are purposefully designed and constructed to serve as unprecedented heterogeneous tandem catalysts to complete dehydrogenative cross-coupling reactions in a short time and under mild reaction conditions (room temperature and light), leading to the high-efficient photosynthesis of 4-quinazolinones.
View Article and Find Full Text PDFThe construction of isotypic high-nuclearity inorganic cages with identical pristine parent structure and increasing nuclearity is highly important for molecular growth and structure-property relationship study, yet it still remains a great challenge. Here, we provide an in situ growth approach for successfully synthesizing a series of new giant hollow polymolybdate dodecahedral cages, , , and , whose structures are growth based on giant polymolybdate cage . Remarkably, they show two pathways of nuclear growth based on , that is, the growth of 10 and 20 Mo centers on the inner and outer surfaces to afford and , respectively, and the growth of 10 Mo centers both on the inner and outer surfaces to give .
View Article and Find Full Text PDFThe Zr(IV) ions are easily hydrolyzed to form oxides, which severely limits the discovery of new structures and applications of Zr-based compounds. In this work, three ferrocene (Fc)-functionalized Zr-oxo clusters (ZrOCs), ZrFc, ZrFc and ZrFc were synthesized through inhibiting the hydrolysis of Zr(IV) ions, which show increased nuclearity and regular structural variation. More importantly, these Fc-functionalized ZrOCs were used as heterogeneous catalysts for the transfer hydrogenation of levulinic acid (LA) and phenol oxidation reactions for the first time, and displayed outstanding catalytic activity.
View Article and Find Full Text PDFThe performance applications (e.g., photocatalysis) of zirconium (Zr) and hafnium (Hf) based complexes are greatly hindered by the limited development of their structures and the relatively inert metal reactivity.
View Article and Find Full Text PDFPhotocatalytic synthesis of hydrogen peroxide (H O ) is a potential clean method, but the long distance between the oxidation and reduction sites in photocatalysts hinders the rapid transfer of photogenerated charges, limiting the improvement of its performance. Here, a metal-organic cage photocatalyst, Co (L-CH ) , is constructed by directly coordinating metal sites (Co sites) used for the O reduction reaction (ORR) with non-metallic sites (imidazole sites of ligands) used for the H O oxidation reaction (WOR), which shortens the transport path of photogenerated electrons and holes, and improves the transport efficiency of charges and activity of the photocatalyst. Therefore, it can be used as an efficient photocatalyst with a rate of as high as 146.
View Article and Find Full Text PDFWhile the difference in catalytic reactivity between mono- and multimetallic sites is often attributed to more than just the number of active sites, still few catalyst model systems have been developed to explore more underlying causal factors. In this work, we have elaborately designed and constructed three stable calix[4]arene (C4A)-functionalized titanium-oxo compounds, , , and , with well-defined crystal structures, increasing nuclearity, and tunable light absorption capacity and energy levels. Among them, and can be taken as model catalysts to compare the differences in reactivity between mono- and multimetallic sites.
View Article and Find Full Text PDFStructural variants of high-nuclearity clusters are extremely important for their modular assembly study and functional expansion, yet the synthesis of such giant structural variants remains a great challenge. Herein, we prepared a lantern-type giant polymolybdate cluster (L-Mo ) containing equal metal nuclearity with the famous Keplerate type Mo (K-Mo ). The skeleton of L-Mo features a rare truncated rhombic triacontrahedron, which is totally different with the truncated icosahedral K-Mo .
View Article and Find Full Text PDFRational design of crystalline catalysts with superior light absorption and charge transfer for efficient photoelectrocatalytic (PEC) reaction coupled with energy recovery remains a great challenge. In this work, we elaborately construct three stable titanium-oxo clusters (TOCs, , , and ) modified with a monofunctionalized ligand (9-anthracenecarboxylic acid (Ac) or ferrocenecarboxylic acid (Fc)) and bifunctionalized ligands (Ac and Fc). They have tunable light-harvesting and charge transfer capacities and thus can serve as outstanding crystalline catalysts to achieve efficient PEC overall reaction, that is, the integration of anodic organic pollutant 4-chlorophenol (4-CP) degradation and cathodic wastewater-to-H conversion.
View Article and Find Full Text PDFMetal-oxo clusters have emerged as advanced proton conductors with well-defined and tunable structures. Nevertheless, the exploitation of metal-oxo clusters with high and stable proton conductivity over a relatively wide temperature range still remains a great challenge. Herein, three sulfate groups decorated zirconium-oxo clusters (Zr , Zr , and Zr ) as proton conductors are reported, which exhibit ultrahigh bulk proton conductivities of 1.
View Article and Find Full Text PDFIncidental affect has an important impact on intertemporal choice (IC). This research aimed to test how positive incidental affect influences IC and its underlying mechanisms. We assumed that positive incidental affect may have a disjunction effect on IC that includes or excludes immediate time.
View Article and Find Full Text PDFLuminescent porous coordination polymers (PCPs) are emerging as attractive oxygen-sensing materials, but they are mostly based on single-wavelength luminometry. Here, we report a special mixed-lanthanide strategy for self-referenced ratiometric oxygen sensing. A series of isostructural, pure-lanthanide, or mixed-lanthanide PCPs, MCF-53(Tb/Eu), were synthesized by solvothermal reactions.
View Article and Find Full Text PDFMuch effort has been devoted to develop new porous structures for methane storage. We report a new porous coordination framework showing exceptional methane uptakes (e.g.
View Article and Find Full Text PDFSeparation of highly similar molecules and understanding the underlying mechanism are of paramount theoretical and practical importance, but visualization of the host-guest structure, energy, or dynamism is very difficult and many details have been overlooked. Here, we report a new porous coordination polymer featuring hierarchical porosity and delicate flexibility, in which the three structural isomers of xylene (also similar disubstituted benzene derivatives) can be efficiently separated with an elution sequence inversed with those for conventional mechanisms. More importantly, the separation mechanism is comprehensively and quantitatively visualized by single-crystal X-ray crystallography coupled with multiple computational simulation methods, in which the small apertures not only fit best the smallest para-isomer like molecular sieves, but also show seemingly trivial yet crucial structural alterations to distinguish the meta- and ortho-isomers via a gating mechanism, while the large channels allow fast guest diffusion and enable the structural/energetic effects to be accumulated in the macroscopic level.
View Article and Find Full Text PDFThree 5,5'-azotetrazolate based Zn(II) and Ni(II) complexes exhibit novel supramolecular structures and emit multi-photoluminescence under laser excitation and the multi-photoluminescence promises a multi-channel signal photoluminescent material.
View Article and Find Full Text PDFSeven isomorphous 1D chain Ln3+ complexes Ln(BTA)(HCOO)(H2O)3 (Ln = Pr (1), Gd (2), Eu (3), Tb (4) Dy (5), Er (6) and Yb (7)), and two formate coordinating and bridging 3D Ln3+ complexes Ln(HCOO)3 (Ln = Pr (8) and Nd (9)) have been synthesized and characterized by single crystal X-ray diffraction analysis. Although the Ln3+ ions in 1-7 have different radius, the trivalent lanthanide ions in 1-7 show the same coordinated environment. The well-defined single crystal structures of 8 and 9 are first samples for formate-bridged Ln3+ metallic complexes.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
December 2007
The title complex, [Cd(C(2)HN(9))(C(10)H(8)N(2))(2)]·0.5C(10)H(8)N(2)·H(2)O, was prepared under hydro-thermal reaction conditions. The asymmetric unit contains the cadmium complex, half a 2,2'-bipyridine solvent mol-ecule and a solvent water mol-ecule.
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