From Carbodiimides to Carbon Dioxide: Quantification of the Electrophilic Reactivities of Heteroallenes

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(18), P. 8383 - 8402

Published: April 27, 2020

Kinetics of the reactions isocyanates, isothiocyanates, carbodiimides, carbon disulfide, and dioxide with carbanions or enamines (reference nucleophiles) have been measured photometrically in acetonitrile DMSO solution at 20 °C. The resulting second-order rate constants previously published reactivity parameters N sN reference nucleophiles were substituted into correlation log k2(20 °C) = sN(N + E) to determine electrophilicity heteroallenes: TsNCO (E -7.69) ≫ PhNCO -15.38) > CS2 -17.70) ≈ PhNCS -18.15) PhNCNPh -20.14) CyNCNCy -30). An approximate value could be derived for CO2 (-16 < E - 11). Quantum chemical calculations performed IEFPCM(DMSO)/B3LYP-D3/6-311+G(d,p) level theory compared experimental Gibbs activation energies. distortion-interaction model was used rationalize different reactivities O- S-substituted heteroallenes. Eventually it is demonstrated that determined this work can as ordering principle literature-known

Language: Английский

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Noble metal-free Cu(i)-anchored NHC-based MOF for highly recyclable fixation of CO₂ under RT and atmospheric pressure conditions

Green Chemistry, Journal Year: 2021, Volume and Issue: 23(14), P. 5195 - 5204

Published: Jan. 1, 2021

Noble metal-free, Cu(i) anchored N-heterocyclic carbene (NHC)-MOF exhibiting highly efficient fixation of CO₂ into oxazolidinones, important building blocks for antibiotics at RT and atmospheric pressure conditions is presented.

Language: Английский

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Liquid‐Metal‐Enabled Mechanical‐Energy‐Induced CO₂ Conversion

Advanced Materials, Journal Year: 2021, Volume and Issue: 34(1)

Published: Oct. 8, 2021

A green carbon capture and conversion technology offering scalability economic viability for mitigating CO2 emissions is reported. The uses suspensions of gallium liquid metal to reduce into carbonaceous solid products O2 at near room temperature. nonpolar nature the interface allows instantaneously exfoliate, hence keeping active sites accessible. co-contributor silver-gallium rods ensures a cyclic sustainable process. overall process relies on mechanical energy as input, which drives nano-dimensional triboelectrochemical reactions. When gallium/silver fluoride mix 7:1 mass ratio employed create reaction material, 92% efficiency obtained remarkably low input 230 kWh (excluding used dissolving ) tonne . This presents an economical solution emissions.

Language: Английский

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Highly-Dispersed Zinc Species on Zeolites for the Continuous and Selective Dehydrogenation of Ethane with CO₂ as a Soft Oxidant

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(5), P. 2819 - 2830

Published: Feb. 16, 2021

We report herein the preparation, characterization, and catalytic performance of a series heterogeneous catalysts featuring highly dispersed zinc sites on zeolitic SSZ-13 ZSM-5 frameworks. The materials are evaluated in CO2-assisted oxidative ethane dehydrogenation, very important reaction for synthesis platform chemicals. In particular, we find that Zn2.92/SSZ-13 exhibits high reactivity conversion C2H6 CO2 ethene selectivity. line with experimental results, show selective character catalyst is due to characteristic compositional structure support its topology can effectively confine molecules. An in-depth molecular analysis via operando studies DFT calculations shows rate-limiting step second C–H bond dissociation give C2H4. addition reduces energy barrier this step, favoring desorption C2H4 while limiting byproduct formation. Overall, work demonstrates breakthrough potential made species zeolites relevant transformations.

Language: Английский

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Fabrication of robust and bifunctional cyclotriphosphazene-based periodic mesoporous organosilicas for efficient CO2 adsorption and catalytic conversion

Chemical Engineering Journal, Journal Year: 2021, Volume and Issue: 418, P. 129360 - 129360

Published: March 18, 2021

Language: Английский

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