Search

Diphenylformamide 1 and bisformamide 9 are shown to be safe reservoirs and sources of CO. Their perfectly selective decarbonylations are achieved in solution at room temperature with potassium and cesium diarylamide catalysts. 1 is obtained in excellent yields directly from triethylammonium formate, which may be the product of CO2 scrubbing with NEt3 and catalytic hydrogenation. 1 thus represents a key intermediate in a low‐temperature rWGS reaction sequence. Moreover, solvent‐free decarbonylations of 1 may be run either in the melt at 70 °C or with 9 even in the solid state at 88 °C with improved atom economy. These simple and practical transition‐metal‐free decarbonylations afford ultra‐pure (i. e. dry and solvent‐free) CO at moderate temperatures and the diarylamines byproducts are recycled as pure compounds. In the absence of catalysts, diarylformamides 1 and 9 are long‐term stable at >200 °C. DFT‐calculations indicate a reaction pathway with a rate‐determining deprotonation of Ph2NC(O)H and barrier‐free CO elimination from Ph2NC(O)−. [ABSTRACT FROM AUTHOR]

The new hydrazine 5H-dibenzo[b,f]azepin-5-amine (2) reacts with P- and Si-electrophiles via deprotonation to afford P(III)-, P(V)-, and TMS-hydrazides 3–8 and with carbonyl electrophiles via acid-free condensation to the N-substituted hydrazones 9–12 that are potential N-alkene ligands. While β-ketohydrazone 9 and α-dihydrazone 10 react with [Mes(Cu)]4, [Cu(NCCCH3)4]2PF6, and FeCl2(THF)1.5 to afford complexes devoid of alkene interaction, [Cu(OTf)]2·C6H6 reacts with the α-keto hydrazone 11 or with N,N dimethyl-hydrazone 12 to form the neutral dimeric Cu(I) complex 18 with bridging Cu(I)–alkene interactions or the tetrahedral cationic complex 19 in which 12 binds as a bidentate hydrazone-alkene ligand, respectively. The surprising stability of the alkene coordination in complexes 18 and 19 prevents substitutions with, e.g., PPh3. [ABSTRACT FROM AUTHOR]

Cu(I)-Hydrido complexes supported by dibenzo[b,f]azepinyl P-alkene hybrid ligands and stabilized by electrostatic interactions in a Cu–H⋯KCl⋯BR3 arrangement can be trapped with CO2 at low temperature to afford Cu(I)-formates. The complexes are isolable with and without a pendant BEt3 group and show strong Cu–O and weak B–O interactions. [ABSTRACT FROM AUTHOR]

The electrochemical reduction of CO2 provides a pathway to a sustainable carbon cycle, allowing for the production of hydrocarbons critical for both chemical industry and mobility. Major engineering challenges need to be met in order to achieve efficient and large‐scale CO2 electrolysis. One central challenge is to find the optimum structure for the gas diffusion electrode at the heart of the electrolyzer. An optimum structure will achieve higher conversion efficiencies, lifetime, and product selectivity at lower cost. Critical structural properties of the electrode span the scale from nanometers to millimeters. To rationalize the optimization process, it behooves us to obtain a fully resolved multi‐scale model of the electrode. This digital twin, produced by bridging scale and employing multiple imaging methods, enables the digital study, simulation, and modification of the structure of the electrode. The model is used to simulate the transport processes vital to the functioning of the electrode thus further advancing the digital twin. Subsequently, it is explored how changes to the structure affect the predicted transport properties. The digital twin presented is only supposed to be the kernel and will be complemented by numerous future works. [ABSTRACT FROM AUTHOR]

The Cover Feature shows how the solvent‐free catalytic decarbonylation of diarylformamides affords very pure CO and makes them ideal solid‐state reservoirs/vectors of CO. The recovered diarylamines are readily formylated back to the formamides with formic acid/triethylamine azeotrope on 30–100 g scales. More information can be found in the Research Article by I. Dindarloo Inaloo, R. Dorta and co‐workers...By Royel Hurtado; Lisha Lou; Lukas Klerner; Iman Dindarloo Inaloo; Frank W. Heineman; Sjoerd Harder; Günter Schmid and Romano DortaReported by Author; Author; Author; Author; Author; Author; Author; Author [Extracted from the article]

We investigated the cobalt polyoxometalate catalyst Ba8[Co9(H2O)6(OH)3(HPO4)2(PW9O34)3] in oxygen evolution reaction for large‐scale water electrolysis. The catalyst was characterized, yielding BET surfaces (8.37 m2/g), crystal water content (8.38%, 44 H2O), elemental analyses and single crystal structures (space group P1̅, a = 19.901(4) Å, b = 21.177(4) Å, c = 24.036(5) Å, α = 92.689(7)°, β = 108.73(7)°, γ = 117.137(6)°, Co9Na16O196.05P5W27, V = 8310(3) Å2 with z = 2; R2final = 0.001). The catalyst was integrated in an industrially applicable membrane electrode assembly and electrochemically characterized. Polarization studies revealed catalyst dissolution in situ, visible as a current density peak (32.2 mA/cm2, 2.2 V) with subsequent collapse (<5 mA/cm2). Galvanostatic experiments showed voltage increase from 2.5 to > 10 V at 10 mA/cm2 tracing back to acid‐mediated decomposition of the anionic POM oxide framework. We deduced insufficient thermodynamic as well as kinetic stability for industrial requirements in PEM water electrolysis. [ABSTRACT FROM AUTHOR]