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1.
Artigo em Inglês | MEDLINE | ID: mdl-31583794

RESUMO

Stimuli-responsive photoluminescent materials have attracted considerable attention owing to their potential applications in security protection because the information recorded directly in materials with static luminescent outputs are usually visible under either ambient or UV light. Herein, we realize reversible information anticounterfeiting by loading a photoswitchable diarylethene derivative into a lanthanide metal-organic framework (MOF). Light triggers the open- and closed-form isomerization of the diarylethene unit, which respectively regulates the inactivation and activation of the photochromic FRET process between the diarylethene acceptor and lanthanide donor, resulting in reversible luminescence on-off switching of the lanthanide emitting center in the MOF host. This photoresponsive host-guest system allows for reversible multiple information pattern visible/invisible transformation by simply alternating the exposure to UV and visible light.

2.
Chem Commun (Camb) ; 55(76): 11402-11405, 2019 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-31482880

RESUMO

We realized that tailoring the pore size/geometry and chemistry, by virtue of alkynyl or naphthalene replacing phenyl within a series of isomorphic MOFs, can optimize methane storage working capacities, affording an exceptionally high working capacity of 203 cm3 (STP) cm-3 at 298 K and 5-80 bar.

3.
Chem Commun (Camb) ; 55(76): 11354-11357, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31483423

RESUMO

In this work, we show that precise control of the pore size and functionality in an ultramicroporous metal-organic framework platform can finely tune the adsorption selectivity between acetylene and carbon dioxide at will.

4.
Sci Adv ; 5(8): eaaw4515, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31414048

RESUMO

Resistive random-access memory (RRAM) has evolved as one of the most promising candidates for the next-generation memory, but bistability for information storage, simultaneous implementation of resistive switching and rectification effects, and a better understanding of switching mechanism are still challenging in this field. Herein, we report a RRAM device based on a chiral metal-organic framework (MOF) FJU-23-H2O with switched hydrogen bond pathway within its channels, exhibiting an ultralow set voltage (~0.2 V), a high ON/OFF ratio (~105), and a high rectification ratio (~105). It is not only the first MOF with voltage-gated proton conduction but also the first single material showing both rectifying and resistive switching effects. By single-crystal x-ray diffraction analyses, the mechanism of the resistive switching has been demonstrated.

5.
Nat Commun ; 10(1): 3861, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31455843

RESUMO

Polychlorinated dibenzo-p-dioxins (PCDDs), as a class of persistent and highly toxic organic pollutants, have been posing a great threat to human health and the environment. The sensing of these compounds is important but challenging. Here, we report a highly stable zirconium-based metal-organic framework (MOF), Zr6O4(OH)8(HCOO)2(CPTTA)2 (BUT-17) with one-dimensional hexagonal channels and phenyl-rich pore surfaces for the recognition and sensing of two representative PCDDs, 2,3-dichlorodibenzo-p-dioxin (BCDD) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), based on the fluorescence quenching. BUT-17 exhibits high sensing ability with the detection limits as low as 27 and 57 part per billion toward BCDD and TCDD, respectively, and is very selective as well without the interference of similar compounds. The recognition of BUT-17 toward BCDD is demonstrated by single-crystal structure of its guest-loaded phase, in which the fluorescence-quenched complexes form between the adsorbed BCDD molecules and the MOF host through π-π stacking and hydrogen bonding interactions.

6.
Dalton Trans ; 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31267121

RESUMO

We reported a microporous MOF FJU-101 with open naphthalene diimide functional groups for room temperature (RT) high methane storage. At RT and 65 bar, the total volumetric CH4 storage capacity of 212 cm3 (STP) cm-3 of FJU-101a is significantly higher than those of the isoreticular MFM-130a and UTSA-40a. The enhanced methane uptake in FJU-101a is attributed to the polar carbonyl sites, which can generate strong electrostatic interactions with CH4 molecules.

7.
J Am Chem Soc ; 141(22): 8737-8740, 2019 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-31117661

RESUMO

Hydrogen-bonded organic framework (HOF)-based catalysts still remain unreported thus far due to their relatively weak stability. In the present work, a robust porous HOF (HOF-19) with a Brunauer-Emmett-Teller surface area of 685 m2 g-1 was reticulated from a cagelike building block, amino-substituted bis(tetraoxacalix[2]arene[2]triazine), depending on the hydrogen bonding with the help of π-π interactions. The postsynthetic metalation of HOF-19 with palladium acetate afforded a palladium(II)-containing heterogeneous catalyst with porous hydrogen-bonded structure retained, which exhibits excellent catalytic performance for the Suzuki-Miyaura coupling reaction with the high isolation yields (96-98%), prominent stability, and good selectivity. More importantly, by simple recrystallization, the catalytic activity of deactivated species can be recovered from the isolation yield 46% to 92% for 4-bromobenzonitrile conversion at the same conditions, revealing the great application potentials of HOF-based catalysts.

8.
Angew Chem Int Ed Engl ; 58(30): 10209-10214, 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31059186

RESUMO

Simultaneous removal of trace amounts of propyne and propadiene from propylene is an important but challenging industrial process. We report herein a class of microporous metal-organic frameworks (NKMOF-1-M) with exceptional water stability and remarkably high uptakes for both propyne and propadiene at low pressures. NKMOF-1-M separated a ternary propyne/propadiene/propylene (0.5 : 0.5 : 99.0) mixture with the highest reported selectivity for the production of polymer-grade propylene (99.996 %) at ambient temperature, as attributed to its strong binding affinity for propyne and propadiene over propylene. Moreover, we were able to visualize propyne and propadiene molecules in the single-crystal structure of NKMOF-1-M through a convenient approach under ambient conditions, which helped to precisely understand the binding sites and affinity for propyne and propadiene. These results provide important guidance on using ultramicroporous MOFs as physisorbent materials.

9.
J Am Chem Soc ; 141(9): 4130-4136, 2019 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-30793890

RESUMO

The pore space partition (PSP) approach has been employed to realize a novel porous MOF (FJU-90) with dual functionalities for the challenging C2H2/CO2 separation under ambient conditions. By virtue of a triangular ligand (Tripp = 2,4,6-tris(4-pyridyl)pyridine), the cylindrical channels in the original FJU-88 have been partitioned into uniformly interconnected pore cavities, leading to the dramatically reduced pore apertures from 12.0 × 9.4 to 5.4 × 5.1 Å2. Narrowing down the pore sizes, the resulting activated FJU-90a takes up a very large amount of C2H2 (180 cm3 g-1) but much less of CO2 (103 cm3 g-1) at 298 K and 1 bar, demonstrating it to be the best porous MOF material for this C2H2/CO2 (50%:50%) separation in terms of the C2H2 gravimetric productivity. IAST calculations, molecular modeling studies, and simulated and experimental breakthrough experiments comprehensively demonstrate that the pore space partition strategy is a very powerful approach to constructing MOFs with dual functionality for challenging gas separation.

10.
Chem Soc Rev ; 48(5): 1362-1389, 2019 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-30676603

RESUMO

Hydrogen-bonded organic frameworks (HOFs) represent an interesting type of polymeric porous materials that can be self-assembled through H-bonding between organic linkers. To realize permanent porosity in HOFs, stable and robust open frameworks can be constructed by judicious selection of rigid molecular building blocks and hydrogen-bonded units with strong H-bonding interactions, in which the framework stability might be further enhanced through framework interpenetration and other types of weak intermolecular interactions such as ππ interactions. Owing to the reversible and flexible nature of H-bonding connections, HOFs show high crystallinity, solution processability, easy healing and purification. These unique advantages enable HOFs to be used as a highly versatile platform for exploring multifunctional porous materials. Here, the bright potential of HOF materials as multifunctional materials is highlighted in some of the most important applications for gas storage and separation, molecular recognition, electric and optical materials, chemical sensing, catalysis, and biomedicine.

11.
Adv Mater ; 31(6): e1806897, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30549115

RESUMO

The development of the photostable higher-order multiphoton-excited (MPE) upconversion single microcrystalline material is fundamentally and technologically important, but very challenging. Here, up to five-photon excited luminescence in a host-guest metal-organic framework (MOF) and perovskite quantum dot (QD) hybrid single crystal ZJU-28⊃MAPbBr3 is shown via an in situ growth approach. Such a MOF strategy not only results in a high QD loading concentration, but also significantly diminishes the aggregation-caused quenching (ACQ) effect, provides effective surface passivation, and greatly reduces the contact of the QDs with the external bad atmosphere due to the confinement effect and protection of the framework. These advantages make the resulting ZJU-28⊃MAPbBr3 single crystals possess high PLQY of ≈51.1%, a high multiphoton action cross-sections that can rival the current highest record (measured in toluene solution), and excellent photostability. These findings liberate the excellent luminescence and nonlinear optical properties of perovskite QDs from the solution system to the solid single-crystal system, which provide a new avenue for the exploitation of high-performance multiphoton excited hybrid single microcrystal for future optoelectronic and micro-nano photonic integration applications.

12.
Nat Mater ; 17(12): 1128-1133, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30397312

RESUMO

There are great challenges in developing efficient adsorbents to replace the currently used and energy-intensive cryogenic distillation processes for olefin/paraffin separation, owing to the similar physical properties of the two molecules. Here we report an ultramicroporous metal-organic framework [Ca(C4O4)(H2O)], synthesized from calcium nitrate and squaric acid, that possesses rigid one-dimensional channels. These apertures are of a similar size to ethylene molecules, but owing to the size, shape and rigidity of the pores, act as molecular sieves to prevent the transport of ethane. The efficiency of this molecular sieve for the separation of ethylene/ethane mixtures is validated by breakthrough experiments with high ethylene productivity under ambient conditions. This material can be easily synthesized at the kilogram scale using an environmentally friendly method and is water-stable, which is important for potential industrial implementation. The strategy of using highly rigid metal-organic frameworks with well defined and rigid pores could also be extended to other porous materials for chemical separation processes.

13.
Artigo em Inglês | MEDLINE | ID: mdl-30398044

RESUMO

A robust nanoporous supramolecular network stabilized by charge-transfer interactions has been successfully constructed based on the bipyridinium and bicarboxylic acid with electron-donating hydroxyl pendant group, which exhibits high durability towards extensive acid/base condition (pH: 2-12), organic solvents and the plucking of metal ions. Furthermore, the separation capacity toward Rhodamine B and other dyes with the same charge and smaller molecular sizes has been realized in it.

14.
Chem Commun (Camb) ; 2018 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-30451265

RESUMO

Nitrous oxide (N2O) is considered as the third most important greenhouse gas after carbon dioxide and methane and needs to be removed from air. Herein, we reported the metal-organic framework MIL-100Cr with open Cr sites for record N2O capture capacities of 5.78 mmol g-1 at 298 K and 8.25 mmol g-1 at 273 K, respectively. DFT calculations showed that the static binding energy of N2O on the open-Cr site is notably higher than that of N2, 72.5 kJ mol-1 vs. 51.6 kJ mol-1, which enforces MIL-100Cr to exhibit extremely high N2O/N2 ideal adsorbed solution theory (IAST) gas separation selectivity up to 1000.

15.
Science ; 362(6413): 443-446, 2018 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-30361370

RESUMO

The separation of ethane from its corresponding ethylene is an important, challenging, and energy-intensive process in the chemical industry. Here we report a microporous metal-organic framework, iron(III) peroxide 2,5-dioxido-1,4-benzenedicarboxylate [Fe2(O2)(dobdc) (dobdc4-: 2,5-dioxido-1,4-benzenedicarboxylate)], with iron (Fe)-peroxo sites for the preferential binding of ethane over ethylene and thus highly selective separation of C2H6/C2H4 Neutron powder diffraction studies and theoretical calculations demonstrate the key role of Fe-peroxo sites for the recognition of ethane. The high performance of Fe2(O2)(dobdc) for the ethane/ethylene separation has been validated by gas sorption isotherms, ideal adsorbed solution theory calculations, and simulated and experimental breakthrough curves. Through a fixed-bed column packed with this porous material, polymer-grade ethylene (99.99% pure) can be straightforwardly produced from ethane/ethylene mixtures during the first adsorption cycle, demonstrating the potential of Fe2(O2)(dobdc) for this important industrial separation with a low energy cost under ambient conditions.

16.
Angew Chem Int Ed Engl ; 57(49): 16020-16025, 2018 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-30304568

RESUMO

Purification of C2 H4 from an C2 H4 /C2 H6 mixture, one of the most important while challenging industrial separation processes, is mainly through energy-intensive cryogenic distillation. Now a family of gallate-based metal-organic framework (MOF) materials is presented, M-gallate (M=Ni, Mg, Co), featuring 3D interconnected zigzag channels, the aperture sizes of which (3.47-3.69 Å) are ideally suitable for molecular sieving of ethylene (3.28×4.18×4.84 Å3 ) and ethane (3.81×4.08×4.82 Å3 ) through molecular cross-section size differentiation. Co-gallate shows an unprecedented IAST selectivity of 52 for C2 H4 over C2 H6 with a C2 H4 uptake of 3.37 mmol g-1 at 298 K and 1 bar, outperforming the state-of-the-art MOF material NOTT-300. Direct breakthrough experiments with equimolar C2 H4 /C2 H6 mixtures confirmed that M-gallate is highly selective for ethylene. The adsorption structure and mechanism of ethylene in the M-gallate was further studied through neutron diffraction experiments.

17.
J Am Chem Soc ; 140(40): 12940-12946, 2018 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-30216725

RESUMO

The separation of ethane from its analogous ethylene is of great importance in the petrochemical industry, but very challenging and energy intensive. Adsorptive separation using C2H6-selective porous materials can directly produce high-purity C2H4 in a single operation but suffers from poor selectivity. Here, we report an approach to boost the separation of C2H6 over C2H4, involving the control of pore structures in two isoreticular ultramicroporous metal-organic framework (MOF) materials with weakly polar pore surface for strengthened binding affinity toward C2H6 over C2H4. Under ambient conditions, the prototypical compound shows a very small uptake difference and selectivity for C2H6/C2H4, whereas its smaller-pore isoreticular analogue exhibits a quite large uptake ratio of 237% (60.0/25.3 cm3 cm-3), remarkably increasing the C2H6/C2H4 selectivity. Neutron powder diffraction studies clearly reveal that the latter material shows self-adaptive sorption behavior for C2H6, which enables it to continuously maintain close van der Waals contacts with C2H6 molecules in its optimized pore structure, thus preferentially binds C2H6 over C2H4. Gas sorption isotherms, crystallographic analyses, molecular modeling, selectivity calculation, and breakthrough experiment comprehensively demonstrate this unique MOF material as an efficient C2H6-selective adsorbent for C2H4 purification.

18.
Angew Chem Int Ed Engl ; 57(46): 15183-15188, 2018 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-30240522

RESUMO

Separation of propyne/propylene (C3 H4 /C3 H6 ) is more difficult and challenging than that of acetylene/ethylene (C2 H2 /C2 H4 ) because of their closer molecular sizes. A comprehensive screening of a series of metal-organic frameworks with broad types of structures, pore sizes, and functionalities was carried out. UTSA-200 was identified as the best separating material for the removal of trace C3 H4 from C3 H4 /C3 H6 mixtures. Gas sorption isotherms reveal that UTSA-200 exhibits by far the highest C3 H4 adsorption capacity (95 cm3 cm-3 at 0.01 bar and 298 K) and record C3 H4 /C3 H6 selectivity, which was mainly attributed to the suitable dynamic pore size to efficiently block the larger C3 H6 molecule whilst the strong binding sites and pore flexibility capture smaller C3 H4 . This material thus provides record purification capacity for the removal of C3 H4 from a 1:99 (or 0.1:99.9, v/v) C3 H4 /C3 H6 mixture to produce 99.9999 % pure C3 H6 with a productivity of 62.0 (or 142.8) mmol g-1 .

19.
Chem Commun (Camb) ; 54(71): 9937-9940, 2018 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-30116816

RESUMO

The new ligand tris(p-carboxyphenylethynyl)phosphine (P{C[triple bond, length as m-dash]CC6H4-4-CO2H}3) was used to synthesize a permanently porous Mn(ii)-based acetylenic phosphine coordination material, PCM-48. This triply-interpenetrated MOF contains 1-D microchannels that are decorated with electron-rich and adsorbate-accessible acetylenic moieties and phosphine lone pairs. PCM-48 has a moderate room-temperature C2H2 adsorption capacity (25.54 cm3 g-1) and displays high separation selectivities for C2H2 over CH4 (C2H2/CH4 = 23.3), CO2 (C2H2/CO2 = 4.3), and N2 (C2H2/N2 = 76.9) at 296 K.

20.
Appl Opt ; 57(22): 6598-6604, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30117901

RESUMO

Photonic quasi-crystals and photonic crystals with certain degrees of disorder can have a broadband light-matter interaction. In this paper, we present the holographic fabrication of graded photonic super-quasi-crystals through pixel-by-pixel phase pattern engineering using a spatial light modulator. Using the same phase pattern arranged in a decagon, we have fabricated graded photonic super-quasi-crystals with five-fold symmetry and multiple levels of gradients and graded photonic super-crystals with rectangular unit super-cells, depending on the Fourier filter. Although a certain degree of disorder was incorporated in the quasi-crystals, we still observed the golden ratio in the diameters of the diffraction rings of the fabricated quasi-crystals, indicating five-fold symmetry. Using direct pixel-by-pixel phase engineering, the same laser projection system, consisting of an integrated spatial light modulator and a reflective optical element, can be used for the fabrication of graded photonic super-crystals with various symmetries. The multi-level gradient effects on the optical properties of an organic light-emitting diode were simulated. When the cathode of an organic light-emitting device is patterned in the graded photonic super-crystals, a light extraction efficiency up to 76% in the visible range can be achieved.

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