Diverse Mechanistic Pathways in Single-Site Heterogeneous Catalysis: Alcohol Conversions Mediated by a High-Valent Carbon-Supported Molybdenum-Dioxo Catalyst

ACS Catalysis ◽  
2022 ◽  
pp. 1247-1257
Author(s):  
Jiaqi Li ◽  
Anusheela Das ◽  
Qing Ma ◽  
Michael J. Bedzyk ◽  
Yosi Kratish ◽  
...  
Keyword(s):  
Heterogeneous Catalysis ◽  
Single Site ◽  
High Valent

scholarly journals Cover Picture: Molecular Heterogeneous Catalysis: A Single-Site Zeolite-Supported Rhodium Complex for Acetylene Cyclotrimerization (Chem. Eur. J. 26/2007)

2007 ◽  
Vol 13 (26) ◽  
pp. 7267-7267
Author(s):  
Philip W. Kletnieks ◽  
Ann J. Liang ◽  
Raluca Craciun ◽  
Justin O. Ehresmann ◽  
David M. Marcus ◽  
...  
Keyword(s):  
Heterogeneous Catalysis ◽  
Single Site ◽  
Rhodium Complex

Molecular Heterogeneous Catalysis: A Single-Site Zeolite-Supported Rhodium Complex for Acetylene Cyclotrimerization

2007 ◽  
Vol 13 (26) ◽  
pp. 7294-7304 ◽  
Author(s):  
Philip W. Kletnieks ◽  
Ann J. Liang ◽  
Raluca Craciun ◽  
Justin O. Ehresmann ◽  
David M. Marcus ◽  
...  
Keyword(s):  
Heterogeneous Catalysis ◽  
Single Site ◽  
Rhodium Complex

scholarly journals Heterogeneous C─H Functionalization in Water via Porous Covalent Organic Framework Nano Films: A Case of Catalytic Sphere Transmutation

2021 ◽  
Author(s):  
Rahul Banerjee ◽  
Himadri Sasmal ◽  
Saikat Bag ◽  
Bittu Chandra ◽  
Poulami Majumder ◽  
...  
Keyword(s):  
Thin Films ◽  
Heterogeneous Catalysis ◽  
Self Assembly ◽  
Reaction Medium ◽  
Practical Implementation ◽  
Organic Substrates ◽  
Covalent Organic Framework ◽  
High Valent ◽  
High Degree ◽  
Organic Framework

Abstract Heterogeneous catalysis in water has not been explored beyond certain advantages like recyclability and recovery of the catalysts from the reaction medium. In doing so, they often fail to address other authentic pitfalls of homogeneous catalysis. Moreover, poor yield, extremely low selectivity, and active catalytic sites' deactivation further underrate the heterogeneous catalysis in water. On the other hand, most of the synthetically useful homogeneous catalysts are either water intolerant or remain catalytically inactive in water. Considering these facts, we have rationally designed and synthesized solution dispersible porous covalent organic framework (COF) nano-spheres to utilize their distinctive morphology and dispersibility to bridge between homogeneous and heterogeneous catalysis. The success has further been extended in fabricating catalyst immobilized COF thin-films via covalent self-assembly for the very first time. We have used these catalyst immobilized COF thin-films to develop a general methodology for the C-H functionalization of organic substrates in water. This unique covalent self-assembly occurs through the protrusion of the fibers/threads at the interface of two nano-spheres, transmuting the catalytic spheres into films without any leaching of catalyst molecules, which was hitherto unheard of. The catalyst immobilized porous COF thin-films' chemical functionality and hydrophobic environment stabilizes the high valent transient active oxoiron(V) intermediate in water and restricts the active catalytic site's deactivation. An elevated catalytic yield and high selectivity (3°:2°) have been achieved in open-air conditions at room temperature, accompanying the elemental feature of heterogeneous catalysis, i.e., the recyclability. These COF films functionalized the unactivated C-H bonds in water with a high catalytic yield (45-99%) and with a high degree of selectivity (cis:trans=155:1; 3°:2°=257:1 in case of cis-1,2-dimethylcyclohexane). To establish the "practical implementation" of this approach, we conducted the inflow catalysis (Turnover Number = 355±5) using catalyst immobilized COF films fabricated on a macroporous polymeric support.

Perioperativer Einsatz der single-site veno-venösen extrakorporalen CO2-Eliminierung (ECCO2R) während single-port VATS Riesenbullaresektion

2017 ◽  
Author(s):  
B Redwan ◽  
C Biancosino ◽  
G Wöbker ◽  
F Giebel ◽  
R Zanner ◽  
...  
Keyword(s):  
Single Port ◽  
Single Site
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