Ratiometric luminescent oxygen sensing based on dual fluorescence and phosphorescence emission in a single matrix is highly desirable, yet the designed synthesis remains challenging. Silver-chalcogenolate-cluster-based metal-organic frameworks that combine the advantages of silver clusters and metal-organic frameworks have displayed unique luminescent properties. Herein, we rationally introduce −NH2 groups on the linkers of a silver-chalcogenolate-cluster-based metal-organic framework (Ag12bpy-NH2) to tune the intersystem crossing, achieving a dual fluorescence-phosphorescence emission from the same linker chromophore. The blue fluorescence component has a 100-nm gap in wavelength and 8,500,000-fold difference in lifetime relative to a yellow phosphorescence component. Ag12bpy-NH2 quantifies oxygen during hypoxia with the limit of detection of as low as 0.1 ppm and 0.3 s response time, which is visualized by the naked eye. Our work shows that metal cluster-based MOFs have great potential in luminescent sensing, and the longer-lived charge-separated states could find more photofunctional applications in solar energy transformation and photocatalysis. Incorporating dual fluorescence and phosphorescence into a single matrix is attractive for oxygen sensing, but material design is challenging. Here the authors achieve dual fluorescence-phosphorescence from a single linker chromophore in a silver chalcogenolate-cluster-based metal-organic framework.
Silver chalcogenide wires are for the first time assembled by linear fluorinated carboxylate ligand into a metal–organic framework (MOF) with multifunctional properties. Fluorinated ligands in the host framework endow the MOF excellent hydrophobicity. More interestingly, it displays typical semiconductivity due to the ordered nanoarray of non-discrete helical (–Ag–S–)n chains.
Monolayer-protected atomically precise silver clusters display low photoluminescence (PL) quantum yield (QY) and susceptibility under ambient conditions, and their chiroptical activities also remain underdeveloped. Here, we report enantiomers of an octahedral Ag6 cluster prepared via one-step synthesis using designed chiral ligands at ambient temperature. These clusters exhibit a highest PLQY (300 K) >95.0% and retain their structural integrity and emission up to 150°C in air. Atomically precise...
Gossypol (Gsp), a natural toxin concentrated in cottonseeds, poses great risks to the safe consumption of cottonseed products which are used extensively throughout the food industry. In this work, we report the first luminescence “turn-on” sensors for Gsp using near infrared emitting lanthanide (Ln3+) materials, including Ln3+ MOFs and Ln3+ salts. We first demonstrate that the Yb3+ photoluminescence of a Yb3+ MOF, Yb-NH2-TPDC, can be employed to selectively detect Gsp with a limit of detection o...
Last. Peng Cheng(NKU: Nankai University)H-Index: 86
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: Metal-organic frameworks (MOFs) with multiple emission centers are newly emerging as ratiometric sensors owing to their high sensitivity and high selectivity toward a wide range of targeted functional species. Energy transfer between the light-absorbing group and emission centers and between different emission centers is the key to rationally design and synthesize MOF-based ratiometric sensors. A good match between the energy levels of the light-absorbing groups and emission centers is the pre...
Last. Omar M. Yaghi(LBNL: Lawrence Berkeley National Laboratory)H-Index: 164
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Coordinative alignment of target small molecules onto a chiral metal–organic framework (MOF-520)provides a powerful method to determine the structures of small molecules through single-crystal X-ray diffraction (SXRD). In this work, the structures of 17 molecules with eight new coordinating functionalities and varying size have been determined by this method, four of which are complex molecules being crystallized for the first time. The chirality of the MOF backbone not only enables enantioselec...
As a monolayered version of nanoscale metal–organic frameworks (nMOFs), nanoscale metal–organic layers (nMOLs) represent an emerging class of highly tunable two-dimensional materials for hierarchical functionalization and with facile access to analytes. Here we report the design of the first nMOL-based biosensor for ratiometric pH and oxygen sensing in mitochondria. Cationic Hf12-Ru nMOL was solvothermally synthesized by laterally connecting Hf12 secondary building units (SBUs) with oxygen-sensi...
#1Wentao Xu(University of California, Berkeley)H-Index: 3
#1Wentao Xu(LBNL: Lawrence Berkeley National Laboratory)H-Index: 1
Last. Omar M. Yaghi(University of California, Berkeley)H-Index: 164
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A new three-dimensional metal–organic framework (MOF) was synthesized by linking ditopic amino functionalized polyoxometalate [N(C4H9)4]3[MnMo6O18{(OCH2)3CNH2}2] with 4-connected tetrahedral tetrakis(4-formylphenyl)methane building units through imine condensation. The structure of this MOF, termed MOF-688, was solved by single crystal X-ray diffraction and found to be triply interpenetrated diamond-based dia topology. Tetrabutylammonium cations fill the pores and balance the charge of the anion...
#1Adam J. Rieth(MIT: Massachusetts Institute of Technology)H-Index: 13
#2Ashley M. Wright(MIT: Massachusetts Institute of Technology)H-Index: 15
Last. Mircea Dincă(MIT: Massachusetts Institute of Technology)H-Index: 64
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Metal–organic frameworks (MOFs) have diverse applications involving the storage, separation and sensing of weakly interacting, high-purity gases. Exposure to impure gas streams and interactions with corrosive and coordinating gases raises the question of chemical robustness; however, the factors that determine the stability of MOFs are not fully understood. Framework materials have been previously categorized as either thermodynamically or kinetically stable, but recent work has elucidated an en...
#1Yusheng Zhou(SYSU: Sun Yat-sen University)H-Index: 5
#2Wei Qin(SYSU: Sun Yat-sen University)H-Index: 35
Last. Guodong Liang(SYSU: Sun Yat-sen University)H-Index: 30
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: An unconventional organic molecule (TBBU) showing obvious long-lived room temperature phosphorescence (RTP) is reported. X-ray single crystal analysis demonstrates that TBBU molecules are packed in a unique fashion with side-by-side arranged intermolecular aromatic rings, which is entirely different from the RTP molecules reported to date. Theoretical calculations verify that the extraordinary intermolecular interaction between neighboring molecules plays an important role in RTP of TBBU cryst...
Abstract Excessive discharge of metal ions, such as Fe3+ and Cr2O72– / CrO42– may bring about potential threats to human health and the ecological environment. Consequently, the assembly of function-oriented materials as effective chemosensors has the vital practical significance. In this article, four metal-organic frameworks (MOFs), namely, {[Co(bptb)0.5(bibp)(H2O)2]·H2O}n (Ι), [Mn4(bptb)2(bibp)3(H2O)4]n (Ⅱ), [Ni2(bptb)(bipy)2(H2O)3]n (Ⅲ) and [Cd3(bptb)2(bipb)3(H2O)4]n (Ⅳ) (H4bptb = 2,4,4',6-b...
Abstract Recently, room temperature phosphorescence (RTP) feature of carbon dots (CDs) has gradually diverted researchers' attention from fluorescence and sparks new research boom due to its ultra-long luminescence lifetime and large Stokes shift. Some attempts have been made to construct CDs-based RTP materials, and had seen some important progress. However, few review articles were published to systematically summarize them. Herein, we summarize the recent synthesis advances of the RTP CDs, ma...
Last. Sheng-Nian Luo(Southwest Jiaotong University)H-Index: 32
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Abstract Three-dimensional carbon honeycombs (3D C-honeycombs) are considered as a promising matrix material for new composites, while their mechanical behaviors under complex stress status remain unclear. Here, shear response of 3D C-honeycombs is systematically investigated with molecular dynamics (MD) simulations and mechanical analysis. Two deformation modes are observed for 3D C-honeycombs under in-plane and out-of-plane shear loading. A mechanical model is proposed to describe the deformat...
Last. Jian-Rong Li(Beijing University of Technology)H-Index: 77
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Abstract null null Hydrophobic property of metal–organic frameworks (MOFs) is not only important for their stability improvement but also has a profound effect on the performance of many applications. The essence of coordination bonds led to most of the MOFs are hydrophilic and hydrophobic MOFs are generally achieved by hydrophobic modification of pore surface. Here, we report the systematic regulation of water adsorption and hydrophobic property of a classical MOF MIL-101(Cr) through post-synth...
#2Boon K. Teo(Ha Tai: Xiamen University)H-Index: 16
Last. Nanfeng Zheng(Ha Tai: Xiamen University)H-Index: 90
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Many metal clusters are intrinsically chiral but are often synthesized as a racemic mixture. By taking chiral Ag14(SPh(CF3)2)12(PPh3)4(DMF)4 (Ag14) clusters with bulky thiolate ligands as an example, we demonstrate herein an interesting assembly disassembly (ASDS) strategy to obtain the corresponding, optically pure crystals of both homochiral enantiomers, R-Ag14m and S-Ag14m. The ASDS strategy makes use of two bidentate linkers with different chiral configurations, namely, (1R,2R,N1E,N2E)-N1,N2...
Last. Yong Sheng Zhao(CAS: Chinese Academy of Sciences)H-Index: 55
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Porous organic frameworks have emerged as the promising platforms to construct tunable microlasers. Most of these microlasers are achieved from metal-organic frameworks via meticulously accommodating the laser dyes with the sacrifice of the pore space, yet they often suffer from the obstacles of either relatively limited gain concentration or sophisticated fabrication techniques. Herein, we reported on the first hydrogen-bonded organic framework (HOF) microlasers with color-tunable performance b...
Last. Jun Chen(NKU: Nankai University)H-Index: 214
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Non-noble transition metal complexes have attracted growing interest as efficient electrocatalysts for oxygen reduction reaction (ORR) while their activities still lack rational and effective regulation. Herein, we propose a d-π conjugation strategy for rough and fine tuning of ORR activity in TM-BTA (TM = Mn/Fe/Co/Ni/Cu, BTA = 1,2,4,5-benzenetetramine) coordination polymers. By first-principle calculations, we elucidate that the strong d-π conjugation elevates the [[EQUATION]] / [[EQUATION]] or...
Last. Zhi-Gang Ren(Soochow University (Suzhou))H-Index: 37
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Trinuclear complex [Au2Ag(dppmaphen)2(CN)2]PF6 photoluminesces on exposure to low molecular weight alcohols. This emission is likely due to C-Hπ interactions between the analyte and -PPh2 group, that inhibits non-radiative relaxation of the photoexcited state. Photoluminescene was quenched by removing the analyte under a stream of N2 or replacing it with H2O. This on/off switching was clearly visible, relatively rapid and recyclable.