Publications by authors named "Guanfeng Ji"

The multifunctional and reversible stimuli-responsive luminescence switching offers significant potential for advanced photonic applications but presents considerable challenges for zero-dimensional (0D) hybrid halides. In this study, we design two 0D Mn(II)-based hybrid halides, (DMAP)MnCl·HO and (DMAP)MnCl (DMAP = protonated 4-dimethylaminopyridine), which demonstrate reversible photoluminescence (PL) and radioluminescence (RL) switching through the removal/insertion of guest HO and single-crystal to single-crystal (SC-SC) transformation. By employing a one-step electrospinning strategy, the composite nanofiber film benefits from geometric confinement and the superior hydrophobicity of the PVDF matrix, exhibiting excellent reversible PL switching properties, remarkable repeatability (1000 cycles), and rapid response to breath (0.

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Article Synopsis
  • Researchers created a biomimetic electrosynthesis method using a coordination capsule with NADH mimics to efficiently produce α-hydroxy/amino esters, mimicking biological systems.
  • The design allowed the metal centers to relay electrons and activate the NADH mimics for hydrogenation of substrates, both with and without natural enzymes.
  • The cobalt capsule showed a significant yield improvement at -1.2 V, achieving 92%, while also demonstrating high performance metrics like a TON of 650 mol and TOF of 185 mol·h, outperforming existing systems.
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Synergistic catalysis is an efficient and powerful strategy for simultaneously activating reactants by multiple active sites to promote the efficiency of difficult and challenging catalytic reactions. Meanwhile, enzymes with multi-active-site synergistic catalytic properties possessing high efficiency and high selectivity have become the goal pursued in the field of catalytic chemistry in recent years. Metal-organic frameworks (MOFs), as an effective heterogeneous catalytic platform, that can integrate multiple active sites for synergistic catalysis like enzymatic systems have recently attracted interest.

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The development of methodologies for inducing and tailoring activities of catalysts is an important issue in various catalysis. The ultrathin 2D monolayer metal-organic framework (MOF) nanosheets with more accessible active sites and faster diffusion obtained by exfoliating 3D layered MOFs are of great potential as heterogeneous catalysts, but the rational design and preparation of 3D layered MOFs remains a grand challenge. Herein, a novel weak electrostatic interaction strategy to construct a 3D layered cerium-bearing MOF by coordinating chlorine-capped cerium nodes and linear photoactive methyl viologen (MV ) organic linkers is used.

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Metal-organic frameworks (MOFs) have gained attention as multifunctional catalytic platforms, allowing us to gain important insights into synergistically activating both C-H bonds and oxygen for improving oxidation. Herein, by ingenious incorporation of anthraquinone, we report an anthraquinone-based MOF as a bifunctional heterogeneous photocatalytic platform to simultaneously activate inert C(sp)-H bonds and oxygen for C-H bond oxidation. Making use of the rigid framework with the fixation and isolation effect, both a great chemical stability and bifunctional synergistic photocatalytic effects were obtained through the immobilization of anthraquinone into a MOF.

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Xanthene dyes as a class of ideal organic homogeneous photocatalyst have received significant attention in C-H bond activation; however, the inherent nature of fast carrier recombination/deactivation and low stability limits their practical applications. Herein, by the ingenious decoration of eosin Y into a porous metal-organic framework (MOF), a high-performance heterogeneous MOF-based photocatalyst was prepared to efficiently activate inert C-H bonds on the reactants via the hydrogen atom transfer pathway for the functionalization of the C-H bonds. Taking advantage of the fixation effect of a rigid framework, the incorporation of eosin Y into MOF leads to great enhancement of their chemical durability.

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Activation and selective functionalization of inert C(sp)-H bonds remain one of the most challenging tasks in current synthetic chemistry. Herein, by decorating vanadium(V)-porphyrin into metal-organic frameworks (MOFs) to stabilize the active tertbutyl peroxide radical, we reported a new approach to accomplish inert C(sp)-H bond activation by a synergistic bimetallic strategy via a hydrogen atom transfer process under mild conditions. The stabilized peroxide radical by V-porphyrin-based MOFs abstracted a hydrogen atom from the inert C(sp)-H bonds for direct oxidization transformation utilizing environmentally friendly oxygen.

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The activation and oxidization of inert C(sp )-H bonds into value-added chemicals affords attractively economic and ecological benefits as well as central challenge in modern chemistry. Inspired by the natural enzymatic transformation, herein, we report a new multiphoton excitation approach to activate the inert C(sp )-H bonds and oxygen by integrating the photoinduced electron transfer (PET), ligand-to-metal charge transfer (LMCT) and hydrogen atom transfer (HAT) events together into one metal-organic framework. The well-modified nicotinamide adenine dinucleotide (NAD ) mimics oxidized Ce -OEt moieties to generate Ce -OEt chromophore and its reduced state mimics NAD via PET.

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A unique metal-organic framework with the formula [Cd(HL)(L)·HO]·3HO (HL = 5,5'-(1H-1,2,4-triazole-3,5-diyl)diisophthalic acid) was successfully constructed under solvothermal conditions. The frameworks with multiple free Lewis base sites and Lewis acid sites exhibited easily sensitized properties. After the encapsulation of Tb cations, the as-synthesized Tb@Cd-MOF demonstrated strong luminescence induced by the efficient energy transfer from the bridging ligands to the Tb cations, with the potential to serve as a chemical sensor.

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A unique three-dimensional luminescent metal-organic framework (Cd-MOFs), [Cd(tpbpc)]·2HO·DMF (Htpbpc = 4'-[4,2';6',4″]-terpyridin-4'-yl-biphenyl-4-carboxylic acid; DMF = dimethylformamide), was synthesized and structurally characterized; it exhibits excellent luminescent property and structural stability in aqueous solutions. Interestingly, an unparalleled luminescence-silent system CrO@Cd-MOFs was successfully fabricated by postsynthetic modification of metal-organic frameworks. This luminescence-silent system represents a highly selective and sensitive turn-on luminescent responding to ascorbic acid.

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The self-assembly of a zinc salt with the novel ligand 4,4',4″-[(1,3,5-triazine-2,4,6-triyl)tris(sulfanediyl)]tribenzoic acid generated 3D microporous metal-organic frameworks (MOFs), namely, {[Zn(L)(O)(HO)]·4EtOH} . The frameworks with multiple Lewis basic sites exhibit easily sensitized properties. After encapsulation of the Tb cation in this Zn-MOF, the as-obtained fluorescent-functionalized Tb@Zn-MOFs not only maintain distinguished chemical stabilities but also exhibit strong characteristic emissions of trivalent terbium ions.

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Benefiting from their porous structures, metal-organic frameworks (MOFs) have attracted intensive attention for use in drug release. However, the controllable synthesis of MOFs with proper particle sizes is still very challenging, which largely limits its applications. Here, UIO-66-NH2 with controlled particle sizes in the range of 20-200 nm has been achieved successfully.

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This work presents for the first time the synthesis of a novel nanoscale Fe-MOFs/Eu-MOFs heterostructure, in which spherical Fe-MOFs with a large surface area were introduced as a matrix for the well-dispersed growth of rodlike Eu-MOFs. The obtained Fe-MOFs/Eu-MOFs materials exhibit excellent magnetic resonance/optical imaging capacity and satisfactory drug delivery behavior.

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A unique metal-organic complex (MOC) with formula [Eu(tpbpc)·CO·4HO]·DMF·solvent (Htpbpc = 4'-[4,2';6',4″]-terpyridin-4'-yl-biphenyl-4-carboxylic acid) has been successfully constructed under solvothermal conditions. The Eu complex, as proved by structural analysis, exhibits a fascinating 1D linear-type chain structure which is further extended to a 3D H-bonded supramolecular framework. The luminescent investigations confirm that the emission behavior of the Eu complex possesses excellent water stability and pH stability, and it is the first example of a MOC-based fluorescent probe with high selectivity, high sensitivity, and low detection limit, targeting Cr(III) and Cr(VI) (CrO/CrO) ions in aqueous solution.

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