A PEGylated Tin Porphyrin Complex for Electrocatalytic Proton Reduction: Mechanistic Insights into Main‐Group‐Element Catalysis

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(34)

Published: June 21, 2022

Abstract Electrocatalytic proton reduction to form dihydrogen (H 2 ) is an effective way store energy in the of chemical bonds. In this study, we validate applicability a main‐group‐element‐based tin porphyrin complex as molecular electrocatalyst for reduction. A PEGylated Sn ( SnPEGP displayed high activity (−4.6 mA cm −2 at −1.7 V vs. Fc/Fc + and selectivity Faradaic efficiency 94 % acetonitrile (MeCN) with trifluoroacetic acid (TFA) source. The maximum turnover frequency (TOF max H production was obtained 1099 s −1 . Spectroelectrochemical analysis, conjunction quantum calculations, suggest that occurs via electron‐chemical‐electron‐chemical (ECEC) pathway. This study reveals catalyst serves novel platform investigating electrocatalytic reactions provides new mechanistic insights into

Language: Английский

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A Multidimensional Approach to Carbodiphosphorane–Bismuth Coordination Chemistry: Cationization, Redox-Flexibility, and Stabilization of a Crystalline Bismuth Hydridoborate

Inorganic Chemistry, Journal Year: 2022, Volume and Issue: 61(48), P. 19452 - 19462

Published: Nov. 22, 2022

Bismuth complexes stabilized by carbon-based donor ligands are underserved their instability, often due to facile ligand dissociation and deleterious protonolysis. Herein, we show that the ortho-bismuthination of hexaphenylcarbodiphosphorane enables a robust framework with geometrically constrained carbone-bismuth bonding interactions, which highly tunable cationization. The carbodiphosphorane bismuth halides (1 2) remarkably air-stable feature unprecedented transcarboneC-Bi-X ligation, resulting in elongated Bi-X bonds. In contrast known complexes, hydrolytic activation carbone yields well-defined organobismuth subsequent dehydrohalogenation is feasible using potassium bis(trimethylsilyl)amide or N-heterocyclic carbenes. redox-flexibility this was evaluated high catalytic activity 1 2 for silylation 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) under mild conditions (50 °C, 24-96 h) low catalyst loadings (5-10 mol %), suggests accessibility short-lived hydridic radical species. reaction 1, PhSiH3, tris(pentafluorophenyl)borane (BCF) first crystallographically characterized hydridoborate complex as an ionic species (9), presumably BCF-mediated hydride abstraction from unobserved [Bi]-H intermediate. All isolated compounds have been heteronuclear NMR spectroscopy X-ray crystallography, situation representative (1, 2, 5, 9) were further density functional theory.

Language: Английский

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Selective Electrocatalytic Reduction of Nitrous Oxide to Dinitrogen with an Iron Porphyrin Complex

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(19), P. 12617 - 12622

Published: Sept. 13, 2023

Nitrous oxide (N2O) is the third largest contributor to anthropogenic greenhouse gas emissions and plays a detrimental role in depletion of ozone. Despite contribution N2O as an atmospheric pollutant, there are currently only few examples electrochemical remediation N2. Herein we report electrocatalytic deoxygenation by iron tetraphenylporphyrin (FeTPP) form N2 with quantitative Faradaic efficiency observed rate 1.91 s–1. No degradation was after controlled potential electrolysis. Mechanistic investigation proposed catalytic steps determined that hydrogen-bond donors critical for accelerating activation proton transfer involved rate-determining step.

Language: Английский

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Reduction of Nitrous Oxide by Light Alcohols Catalysed by a Low‐Valent Ruthenium Diazadiene Complex

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(20)

Published: Jan. 18, 2023

Decomposition of the environmentally harmful gas nitrous oxide (N2 O) is usually performed thermally or catalytically. Selective catalytic reduction (SCR) currently most promising technology for N2 O mitigation, a multicomponent heterogeneous system that employs reducing agents such as ammonia, hydrogen, hydrocarbons, combination thereof. This study reports first homogenous catalyst performs employing readily available and cheap light alcohols methanol, ethanol ethylene glycol derivatives. During reaction, these are transformed in dehydrogenative coupling reaction to carboxylate derivatives, while converted H2 O, later entering substrate. The catalysed by low-valent dinuclear ruthenium complex [Ru2 H(μ-H)(Me2 dad)(dbcot)2 ] carries diazabutadiene, Me2 dad, two rigid dienes, dbcot, ligands. proceeds with low loadings under relatively mild conditions (65-80 °C, 1.4 bar achieving turnover numbers up 480 frequencies 56 h-1 .

Language: Английский

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Insertion of CO₂and CS₂into Bi–N bonds enables catalyzed CH-activation and light-induced bismuthinidene transfer

Chemical Science, Journal Year: 2023, Volume and Issue: 14(19), P. 5214 - 5219

Published: Jan. 1, 2023

CO 2 and CS cleanly insert into Bi–N bonds of cationic bismuth amides. The insertion products are metastable undergo either elimination along with CH activation or light-induced bismuth( i ) triflate C–S bond formation.

Language: Английский

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