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1.
J Am Chem Soc ; 2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32036654

RESUMO

Conventionally, z-direction modulation of two-dimensional covalent organic frameworks (2D-COFs) is difficult to achieve because they rely on spontaneous π-π interactions to form 3D architectures. Herein, we report a facile construction of a novel intercalated covalent organic framework (Intercalated-COF) by synchronizing operations of supramolecular donor-acceptor (D-A) interactions (A unit: 2,5,8,11-tetra(p-formylphenyl)-perylene diimide (PDI) 1; D unit: perylene 3, as intercalator) in the vertical directions, with polymerizations (by only reacting 1 with p-phenylenediamine 2) in the lateral directions. In this Intercalated-COF, the PDI-based covalent 2D layers are uniformly separated by perylene guest layers. This supramolecular strategy opens the possibility for z-direction modulation of 2D-COFs through "intercalating" various guest molecules and thus may contribute to the exploration of advanced applications of these porous and crystalline frameworks.

2.
Angew Chem Int Ed Engl ; 59(11): 4401-4405, 2020 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-31849167

RESUMO

Commercial ultrafiltration membranes have proliferated globally for water treatment. However, their pore sizes are too large to sieve gases. Conjugated microporous polymers (CMPs) feature well-developed microporosity yet are difficult to be fabricated into membranes. Herein, we report a strategy to prepare molecular-sieving membranes by partitioning the mesoscopic channels in water ultrafiltration membrane (PSU) into ultra-micropores by space-confined polymerization of multi-functionalized rigid building units. Nine CMP@PSU membranes were obtained, and their separation performance for H2 /CO2 , H2 /N2 , and H2 /CH4 pairs surpass the Robeson upper bound and rival against the best of those reported membranes. Furthermore, highly crosslinked skeletons inside the channels result in the structural robustness and transfer into the excellent aging resistance of the CMP@PSU. This strategy may shed light on the design and fabrication of high-performance polymeric gas separation membranes.

3.
Artigo em Inglês | MEDLINE | ID: mdl-31833644

RESUMO

Metal-organic frameworks (MOFs) with long-term stability and reversible high water uptake properties can be ideal candidates for water harvesting and indoor humidity control. Now, a mesoporous and highly stable MOF, BIT-66 is presented that has indoor humidity control capability and a photocatalytic bacteriostatic effect. BIT-66 (V3 (O)3 (H2 O)(BTB)2 ), possesses prominent moisture tunability in the range of 45-60 % RH and a water uptake and working capacity of 71 and 55 wt %, respectively, showing good recyclability and excellent performance in water adsorption-desorption cycles. Importantly, this MOF demonstrates a unique photocatalytic bacteriostatic behavior under visible light, which can effectively ameliorate the bacteria and/or mold breeding problem in water adsorbing materials.

4.
Chemistry ; 25(68): 15488-15492, 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31560407

RESUMO

Two-dimensional covalent organic frameworks were synthesized in high yields by polycondensation in nonvolatile ionic liquids. The resulting crystallites are highly porous and exhibit exceptional capability of removing bisphenol A from water. The one reported is a general method to synthesize microporous and mesoporous frameworks, it allows to achieve regular macroscopic shapes, and it is effective in a wide range of reaction temperatures.

5.
Angew Chem Int Ed Engl ; 58(26): 8768-8772, 2019 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-31050847

RESUMO

Membrane technologies that do not rely on heat for industrial gas separation would lower global energy cost. While polymeric, inorganic, and mixed-matrix separation membranes have been rapidly developed, the bottleneck is balancing the processability, selectivity, and permeability. Reported here is a softness adjustment of rigid networks (SARs) strategy to produce flexible, stand-alone, and molecular-sieving membranes by electropolymerization. Here, 14 membranes were rationally designed and synthesized and their gas separation ability and mechanical performance were studied. The separation performance of the membranes for H2 /CO2 , H2 /N2 , and H2 /CH4 can exceed the Robeson upper bound, among which, H2 /CO2 separation selectivity reaches 50 with 626 Barrer of H2 permeability. The long-term and chemical stability tests demonstrate their potential for industrial applications. This simple, scalable, and cost-effective strategy holds promise for the design other polymers for key energy-intensive separations.

6.
J Am Chem Soc ; 141(5): 1923-1927, 2019 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-30657664

RESUMO

Covalent organic frameworks (COFs) with well-tailored channels are able to accommodate ions and offer their conduction pathway. However, due to strong Coulombic interaction and the lack of transport medium, directly including lithium salts into the channels of COFs results in limited ion transport capability. Herein, we propose a strategy of incorporating low-molecular-weight polyethylene glycol (PEG) into COFs with anionic, neutral, or cationic skeletons to accelerate Li+ conduction. The PEG confined in the well-aligned channels retains high flexibility and Li+ solvating ability. The ion conductivity of PEG included in a cationic COF can reach 1.78 × 10-3 S cm-1 at 120 °C. The simplicity of this strategy as well as the diversity of crystalline porous materials holds great promise to design high-performance all-solid-state ion conductors.

7.
Angew Chem Int Ed Engl ; 58(13): 4221-4226, 2019 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-30694606

RESUMO

Conjugated microporous polymers (CMPs) have full access to the organic synthesis toolbox and feature-rich functionality, structural diversity, and high surface area. We incorporated ferrocene (Fc) into the backbones of CMPs and systematically engineered their optical energy gaps. Compared with the CMPs without Fc units yet adopting a similar molecular orbital level, Fc-based CMPs can sufficiently generate reactive oxygen species (ROS) under visible light. The resultant ROS are able to effectively decompose the absorbed pollutants, including organic dyes and chemical warfare agents. Specifically, Fc-based CMPs significantly outperform commercial TiO2 (P25) in the degradation of methylene blue and are capable of converting 2-chloroethyl ethyl sulfide (a mustard gas simulant) into a completely nontoxic product.

8.
Angew Chem Int Ed Engl ; 57(50): 16501-16505, 2018 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-30334322

RESUMO

Covalent organic framework (COF) films combine the processability of polymers with the porosity and atomic precision of crystalline porous materials, properties that are long-sought-after in electronics yet hard to realize. Herein, we prepared four flexible COF films with different alkoxy side chains via interfacial polymerization. The COF films exhibit an ultralow dielectric constant (κ=1.19±0.04 at 105  Hz), small dielectric loss (<0.02, 103 -106  Hz), high breakdown voltage (>63 kV cm-1 ) and low leakage current (10-10  A cm-2 at 1 kV cm-1 ). They have considerable mechanical strength, and ability to withstand high humidity (RH 70 % for 10 days) and repeated bending (1000 times) without losing their dielectric properties. Extension of the alkoxy chains reduces the film's κ and enhances its moisture resistance, while incorporation of guest molecules further increase the κ value up to 43 times.

9.
J Am Chem Soc ; 139(12): 4258-4261, 2017 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-28316238

RESUMO

Covalent organic frameworks (COFs) have attracted growing interest by virtue of their structural diversity and tunability. Herein, we present a novel approach for the development of organic rechargeable battery cathodes in which three distinct redox-active COFs were successfully prepared and delaminated into 2D few-layer nanosheets. Compared with the pristine COFs, the exfoliated COFs with shorter Li+ diffusion pathways allow a significant higher utilization efficiency of redox sites and faster kinetics for lithium storage. Unlike diffusion-controlled manners in the bulk COFs, the redox reactions in ECOFs are mainly dominated by charge transfer process. The capacity and potential are further engineered by reticular design of COFs without altering the underlying topology. Specifically, DAAQ-ECOF exhibits excellent rechargeability (98% capacity retention after 1800 cycles) and fast charge-discharge ability (74% retention at 500 mA g-1 as compared to at 20 mA g-1). DABQ-ECOF shows a specific capacity of 210 mA h g-1 and a voltage plateau of 2.8 V.

10.
J Asian Nat Prod Res ; 18(7): 677-83, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26828227

RESUMO

A facile synthetic approach for total synthesis of tanshinone I has been accomplished. The key precursor is a novel compound, epoxy phenanthraquinone. And this synthesis of tanshinone I is achieved in only three simple stages, which include Diels-Alder reaction, Δ(2)-Weitz-Scheffer-type epoxidation, and Feist-Bénary reaction from commercially available styrene.


Assuntos
/síntese química , Estireno/química , /química , Modelos Moleculares , Estrutura Molecular , Raízes de Plantas/química , Salvia/química , Estereoisomerismo
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