Microenvironments Enabled by Covalent Organic Framework Linkages for Modulating Active Metal Species in Photocatalytic CO 2 Reduction

2022 ◽  
pp. 2110694
Author(s):  
Shuailong Yang ◽  
Rongjian Sa ◽  
Hong Zhong ◽  
Haowei Lv ◽  
Daqiang Yuan ◽  
...  
Keyword(s):  
Metal Species ◽  
Covalent Organic Framework ◽  
Active Metal ◽  
Organic Framework

Tuning the pore structures and photocatalytic properties of a 2D covalent organic framework with multi-branched photoactive moieties

Nanoscale ◽  
2020 ◽  
Vol 12 (30) ◽  
pp. 16136-16142
Author(s):  
Xuan Wang ◽  
Ming-Jie Dong ◽  
Chuan-De Wu
Keyword(s):  
Photocatalytic Properties ◽  
Effective Strategy ◽  
Covalent Organic Framework ◽  
Highly Efficient ◽  
Pore Structures ◽  
Local Connection ◽  
Organic Framework

An effective strategy to incorporate accessible metalloporphyrin photoactive sites into 2D COFs by establishing a 3D local connection for highly efficient photocatalysis was developed.

A Three-Dimensional Tetraphenylethylene-Based Fluorescence Covalent Organic Framework for Molecular Recognition

2020 ◽  
Author(s):  
Junxia Ren ◽  
Yaozu Liu ◽  
Xin Zhu ◽  
Yangyang Pan ◽  
Yujie Wang ◽  
...  
Keyword(s):  
Molecular Recognition ◽  
Fluorescence Probe ◽  
Three Dimensional ◽  
Hazardous Substances ◽  
Covalent Organic Framework ◽  
Highly Sensitive ◽  
Volatile Organic ◽  
Polycyclic Aromatic ◽  
Better Than ◽  
Organic Framework

<p><a></a><a></a><a></a><a></a><a></a><a></a><a></a><a>The development of highly-sensitive recognition of </a><a></a><a></a><a></a><a></a><a>hazardous </a>chemicals, such as volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs), is of significant importance because of their widespread social concerns related to environment and human health. Here, we report a three-dimensional (3D) covalent organic framework (COF, termed JUC-555) bearing tetraphenylethylene (TPE) side chains as an aggregation-induced emission (AIE) fluorescence probe for sensitive molecular recognition.<a></a><a> </a>Due to the rotational restriction of TPE rotors in highly interpenetrated framework after inclusion of dimethylformamide (DMF), JUC-555 shows impressive AIE-based strong fluorescence. Meanwhile, owing to the large pore size (11.4 Å) and suitable intermolecular distance of aligned TPE (7.2 Å) in JUC-555, the obtained material demonstrates an excellent performance in the molecular recognition of hazardous chemicals, e.g., nitroaromatic explosives, PAHs, and even thiophene compounds, via a fluorescent quenching mechanism. The quenching constant (<i>K</i><sub>SV</sub>) is two orders of magnitude better than those of other fluorescence-based porous materials reported to date. This research thus opens 3D functionalized COFs as a promising identification tool for environmentally hazardous substances.</p>

Piperazine as an Inexpensive and Efficient Ligand for Pd-Catalyzed Homocoupling Reactions to Synthesize Bipyridines and Their Analogues

2019 ◽  
Vol 16 (1) ◽  
pp. 173-180
Author(s):  
Mingwei Chen ◽  
Jinyu Hu ◽  
Xiaoli Tang ◽  
Qiming Zhu
Keyword(s):  
Transition Metal ◽  
Oxidation State ◽  
Coupling Reaction ◽  
Aryl Halides ◽  
Metal Species ◽  
Good Substrate ◽  
Active Metal ◽  
Homocoupling Reaction ◽  
Catalytic Cycles ◽  
Reductive Homocoupling

Aim and Objective: The synthesis of bipyridines, especially 2, 2’-bipyridines, remains challenging because the catalytic cycle can be inhibited due to coordination of bipyridine to transition metal. Thus, the development of efficient methods for the synthesis of bipyridines is highly desirable. In the present work, we presented a promising approach for preparation of bipyridines via a Pd-catalyzed reductive homocoupling reaction with simple piperazine as a ligand. Materials and Methods: Simple and inexpensive piperazine was used as a ligand for Pd-catalyzed homocoupling reaction. The combination of Pd(OAc)2 and piperazine in dimethylformamide (DMF) was observed to form an excellent catalyst and efficiently catalyzed the homocoupling of azaarenyl halides, in which DMF was used as the solvent without excess reductants although stoichiometric reductant was generally required to generate the low-oxidation-state active metal species in the catalytic cycles. </P><P> Results: In this case, good to excellent yields of bipyridines and their (hetero) aromatic analogues were obtained in the presence of 2.5 mol% of Pd(OAc)2 and 5 mol% of piperazine, using K3PO4 as a base in DMF at 140°C. Conclusion: According to the results, piperazine as an inexpensive and efficient ligand was used in the Pd(OAc)2-catalyzed homocoupling reaction of heteroaryl and aryl halides. The coupling reaction was operationally simple and displayed good substrate compatibility.

scholarly journals 18.1% single palladium atom catalysts on mesoporous covalent organic framework for gas phase hydrogenation of ethylene

2021 ◽  
Vol 2 (7) ◽  
pp. 100495
Author(s):  
Chun-Te Kuo ◽  
Yubing Lu ◽  
Pezhman Arab ◽  
K. Shamara Weeraratne ◽  
Hani El-Kaderi ◽  
...  
Keyword(s):  
Gas Phase ◽  
Palladium Atom ◽  
Covalent Organic Framework ◽  
Hydrogenation Of Ethylene ◽  
Organic Framework

An Ultrastable Crystalline Acylhydrazone‐Linked Covalent Organic Framework for Efficient Removal of Organic Micropollutants from Water

2021 ◽  
Author(s):  
Yuling Zhao ◽  
Yue Zhao ◽  
Cailing Wu ◽  
Jikuan Qiu ◽  
Huiyong Wang ◽  
...  
Keyword(s):  
Organic Micropollutants ◽  
Efficient Removal ◽  
Covalent Organic Framework ◽  
Organic Framework

scholarly journals CN linked covalent organic framework for the efficient adsorption of iodine in vapor and solution

RSC Advances ◽  
2021 ◽  
Vol 11 (18) ◽  
pp. 10512-10523
Author(s):  
Sanan Song ◽  
Yue Shi ◽  
Ning Liu ◽  
Fengqi Liu
Keyword(s):  
Public Safety ◽  
Nuclear Wastes ◽  
Covalent Organic Framework ◽  
Organic Framework

Volatile nuclear wastes, such as iodine, have received worldwide attention because it poses risks to public safety and pollutes the environment.

scholarly journals Covalent organic framework nanofluidic membrane as a platform for highly sensitive bionic thermosensation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pengcheng Zhang ◽  
Sifan Chen ◽  
Changjia Zhu ◽  
Linxiao Hou ◽  
Weipeng Xian ◽  
...  
Keyword(s):  
Thermal Sensation ◽  
Biological Response ◽  
Covalent Organic Framework ◽  
Physiological Processes ◽  
Potential Applicability ◽  
Continuous Potential ◽  
Temperature Stimulus ◽  
Nanofluidic System ◽  
Response To Temperature ◽  
Organic Framework

AbstractThermal sensation, which is the conversion of a temperature stimulus into a biological response, is the basis of the fundamental physiological processes that occur ubiquitously in all organisms from bacteria to mammals. Significant efforts have been devoted to fabricating artificial membranes that can mimic the delicate functions of nature; however, the design of a bionic thermometer remains in its infancy. Herein, we report a nanofluidic membrane based on an ionic covalent organic framework (COF) that is capable of intelligently monitoring temperature variations and expressing it in the form of continuous potential differences. The high density of the charged sites present in the sub-nanochannels renders superior permselectivity to the resulting nanofluidic system, leading to a high thermosensation sensitivity of 1.27 mV K−1, thereby outperforming any known natural system. The potential applicability of the developed system is illustrated by its excellent tolerance toward a broad range of salt concentrations, wide working temperatures, synchronous response to temperature stimulation, and long-term ultrastability. Therefore, our study pioneers a way to explore COFs for mimicking the sophisticated signaling system observed in the nature.

Pure Crystalline Covalent Organic Framework Aerogels

2021 ◽  
Author(s):  
Dongyang Zhu ◽  
Yifan Zhu ◽  
Qianqian Yan ◽  
Morgan Barnes ◽  
Fangxin Liu ◽  
...  
Keyword(s):  
Covalent Organic Framework ◽  
Organic Framework
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