scholarly journals Kinetics of Hydride Transfer from Catalytic Metal-Free Hydride Donors to CO2

2021 ◽  
Vol 12 (9) ◽  
pp. 2306-2311
Author(s):  
Ravindra B. Weerasooriya ◽  
Jonathan L. Gesiorski ◽  
Abdulaziz Alherz ◽  
Stefan Ilic ◽  
George N. Hargenrader ◽  
...  
Keyword(s):  
Hydride Transfer ◽  
Metal Free ◽  
Catalytic Metal ◽  
Kinetics Of

scholarly journals Kinetics of Hydride Transfer from Metal-Free Hydride Donors to CO2

2020 ◽  
Author(s):  
Ravindra Weerasooriya ◽  
Jonathan L. Gesiorski ◽  
Abdulaziz Alherz ◽  
Stefan Ilic ◽  
George Hargenrader ◽  
...  
Keyword(s):  
Reaction Kinetics ◽  
Driving Force ◽  
Selective Reduction ◽  
Hydride Transfer ◽  
Metal Free ◽  
Thermodynamic Driving Force ◽  
Solar Conversion ◽  
Reorganization Energies ◽  
Kinetics Of ◽  
Kinetic Barriers

Selective reduction of CO<sub>2</sub> to formate represents an ongoing challenge in photoelectrocatalysis. To provide mechanistic insights, we investigate the kinetics of hydride transfer (HT) from a series of metal-free hydride donors to CO<sub>2</sub>. The observed dependence of experimental and calculated HT barriers on the thermodynamic driving force was modeled using the Marcus hydride transfer formalism to obtain the insights into the effect of reorganization energies on the reaction kinetics. Our results indicate that, even if the most ideal hydride donor were discovered, the HT to CO<sub>2</sub> would exhibit sluggish kinetics (less than 100 turnovers at 0.1 eV driving force), indicating that the conventional HT may not be an appropriate mechanism for Solar conversion of CO<sub>2</sub> to formate. We propose that the conventional HT mechanism should not be considered for CO<sub>2</sub> reduction catalysis and argue that the orthogonal HT mechanism, previously proposed to address thermodynamic limitations of this reaction, may also lead to lower kinetic barriers for CO<sub>2</sub> reduction to formate.

scholarly journals Kinetics of Hydride Transfer from Metal-Free Hydride Donors to CO2

2020 ◽  
Author(s):  
Ravindra Weerasooriya ◽  
Jonathan L. Gesiorski ◽  
Abdulaziz Alherz ◽  
Stefan Ilic ◽  
George Hargenrader ◽  
...  
Keyword(s):  
Reaction Kinetics ◽  
Driving Force ◽  
Selective Reduction ◽  
Hydride Transfer ◽  
Metal Free ◽  
Thermodynamic Driving Force ◽  
Solar Conversion ◽  
Reorganization Energies ◽  
Kinetics Of ◽  
Kinetic Barriers

Selective reduction of CO<sub>2</sub> to formate represents an ongoing challenge in photoelectrocatalysis. To provide mechanistic insights, we investigate the kinetics of hydride transfer (HT) from a series of metal-free hydride donors to CO<sub>2</sub>. The observed dependence of experimental and calculated HT barriers on the thermodynamic driving force was modeled using the Marcus hydride transfer formalism to obtain the insights into the effect of reorganization energies on the reaction kinetics. Our results indicate that, even if the most ideal hydride donor were discovered, the HT to CO<sub>2</sub> would exhibit sluggish kinetics (less than 100 turnovers at 0.1 eV driving force), indicating that the conventional HT may not be an appropriate mechanism for Solar conversion of CO<sub>2</sub> to formate. We propose that the conventional HT mechanism should not be considered for CO<sub>2</sub> reduction catalysis and argue that the orthogonal HT mechanism, previously proposed to address thermodynamic limitations of this reaction, may also lead to lower kinetic barriers for CO<sub>2</sub> reduction to formate.

Catalytic metal-free intramolecular hydroaminations of non-activated aminoalkenes: A computational exploration

2012 ◽  
Vol 41 (30) ◽  
pp. 9091 ◽  
Author(s):  
Haixia Li ◽  
Mingwei Wen ◽  
Gang Lu ◽  
Zhi-Xiang Wang
Keyword(s):  
Metal Free ◽  
Computational Exploration ◽  
Catalytic Metal

Reaction Kinetics of Poly-Si Etching in TMAH Solution

2021 ◽  
Vol 314 ◽  
pp. 60-65
Author(s):  
Taegun Park ◽  
Sangwoo Lim
Keyword(s):  
Reaction Kinetics ◽  
Alkaline Solution ◽  
Etching Rate ◽  
Tetramethylammonium Hydroxide ◽  
Dissolved Gas ◽  
Metal Free ◽  
Effect Of Water ◽  
Detailed Kinetics ◽  
Kinetics Of ◽  
Tmah Solution

Tetramethylammonium hydroxide (TMAH) is a metal-free strong alkaline solution which can etch poly-Si. The concentration of dissolved gas as well as the concentration of TMAH affects etching rate of poly-Si. The detailed kinetics of poly-Si etching in TMAH solution is investigated in this study. The effect of water and TMAH concentration on the etching kinetics of poly-Si was investigated by using various concentrations of TMAH solution. It is found that H2O in TMAH solution plays an important role in etching poly-Si. Presence of dissolved CO2 and O2 in TMAH solution tends to inhibit etching of poly-Si. The concentration of dissolved CO2 and O2 in TMAH were reduced by Ar bubbling, thereby the poly-Si etching rate increased.

Metal-Free Iodoperfluoroalkylation: Photocatalysis versus Frustrated Lewis Pair Catalysis

Synthesis ◽  
2020 ◽  
Vol 53 (01) ◽  
pp. 123-134
Author(s):  
Constantin Czekelius ◽  
Lucas Helmecke ◽  
Michael Spittler ◽  
Bernd M. Schmidt
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Irradiation ◽  
Reaction Pathways ◽  
Frustrated Lewis Pairs ◽  
Metal Free ◽  
Comprehensive Account ◽  
Frustrated Lewis Pair ◽  
Catalytic Metal ◽  
Lewis Pairs

A comparison of two catalytic, metal-free iodoperfluoro­alkylation protocols is presented. Frustrated Lewis pairs [ t Bu3P/B(C6F5)3] or phosphines/phosphites under visible light irradiation efficiently mediate the functionalization of non-activated alkenes and alkynes. A comprehensive account of the corresponding substrate scopes as well as insights into the mechanistic details of both reaction pathways are provided.

Catalytic metal-free formation of multi-walled carbon nanotubes in atmospheric arc discharge

Carbon ◽  
2012 ◽  
Vol 50 (12) ◽  
pp. 4588-4595 ◽  
Author(s):  
Yoong Ahm Kim ◽  
Hiroyuki Muramatsu ◽  
Takuya Hayashi ◽  
Morinobu Endo
Keyword(s):  
Carbon Nanotubes ◽  
Arc Discharge ◽  
Metal Free ◽  
Multi Walled Carbon Nanotubes ◽  
Catalytic Metal ◽  
Walled Carbon Nanotubes

Catalytic, Metal‐Free Oxidation of Primary Amines to Nitriles

2019 ◽  
pp. 60-79
Author(s):  
Kyle M. Lambert ◽  
Sherif A. Eldirany ◽  
James M. Bobbitt ◽  
William F. Bailey* ◽  
Thomas R. DeVino ◽  
...  
Keyword(s):  
Primary Amines ◽  
Metal Free ◽  
Catalytic Metal ◽  
Free Oxidation

Hydride transfer reactions. A kinetic study of oxidation of 10-methyl-9-phenylacridan by some π acceptors and a one-electron oxidant

1985 ◽  
Vol 63 (8) ◽  
pp. 2237-2240 ◽  
Author(s):  
Allan K. Colter ◽  
A. Gregg Parsons ◽  
Karen Foohey
Keyword(s):  
Kinetic Study ◽  
Kinetic Isotope Effect ◽  
Isotope Effects ◽  
Hydride Transfer ◽  
Transfer Reactions ◽  
Kinetics Of Oxidation ◽  
Kinetic Isotope ◽  
One Step ◽  
The One ◽  
Kinetics Of

The kinetics of oxidation of 10-methyl-9-phenylacridan (1(H)) and 9-deuterio-10-methyl-9-phenylacridan (1(D)) to 10-methyl-9-phenylacridinium ion (3) by eight oxidants have been investigated. The oxidants included the π-acceptors 1,4-benzoquinone (BQ), 7,7,8,8-tetracyanoquinodimethane (TCNQ), p-bromanil (BA), p-chloranil (CA), tetracyanoethylene (TCNE), 2,3-dicyano-1,4-benzoquinone (DCBQ) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in acetonitrile (AN), BQ in 50:50 (v/v) AN-water, and the one-electron oxidant tris(2,2′-bipyridyl)cobalt(III), [Formula: see text] in AN. The seven π acceptors cover a 109-fold range of reactivity from BQ to DDQ and the deuterium kinetic isotope effect varies from 11.9 (BQ in AN) to 5.8 (DDQ). For π acceptors (BQ, TCNQ, CA, TCNE, and DCBQ) previously investigated with 10-methylacridan (NMA), 1(H) is less reactive than NMA by factors ranging from 9.1 (BQ) to 1.7 × 102 (TCNE). The isotope effects and relative reactivities for the π acceptor oxidations are most simply explained by a one-step hydride transfer mechanism.

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