1,721,079 research outputs found
Two catalysts are better than one
No full textElectroreduction of N2 to ammonia is a possible alternative to the Haber–Bosch process, but the competing hydrogen evolution reaction typically limits yields. Now, electrochemical protocols combining two molecular catalysts are shown to produce ammonia with adequate selectivity at moderate overpotentials under mild conditions
Proton‐Coupled Electron Transfer Reactions Catalysed by 3 d Metal Complexes
No full textProton-coupled electron transfer (PCET) reactions are essential for a wide range of natural energy-conversion reactions and recently, the impact of PCET pathways has been exploited in artificial systems, too. The Minireview highlights PCET reactions catalysed by first-row transition-metal complexes, with a focus on the water oxidation, the oxygen reduction, the hydrogen evolution, and the CO2 reduction reaction. Special attention will be paid to systems in which the impact of such pathways is deduced by comparison to systems with electron-only-transfer pathways.DFG [SI 1577/2-1
A trispyrazolylborato iron Malonato complex as a functional model for the acetylacetone dioxygenase
No full text
2,2'-Bipyridine Equipped with a Disulfide/Dithiol Switch for Coupled Two Electron and Proton Transfer
Full text link[1,2]dithiino[4,3-b:5,6-b´]dipyridine (1) and its protonated open form 3,3´-dithiol-2,2´-bipyridine (2) were synthesised and their interconversion investigated. The X-ray structure of 2 revealed an anti orientation of the two pyridine units and a zwitterionic form. In depth electrochemical studies in combination with DFT calculations lead to a comprehensive picture of the redox chemistry of 1 in the absence and presence of protons. Initial one electron reduction at E1 = −1.97 V results in the formation of the radical anion 1red with much elongated S-S bond, which readily undergoes further reduction at E2 = −2.15 V. Water triggers a potential inversion (E ≥ −1.9 V for the second reduction) as the radical anion 1red is protonated at its basic N atom. DFT studies revealed that S−S bond breaking and twisting of the pyridine units generally occurs after the second reduction step while the potential inversion induced by protonation is a result of charge compensation. The CV data were simulated to derive rate constants for the individual chemical and electrochemical reactions for both scenarios in the absence and presence of protons.Fil: Cattaneo, Mauricio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Química del Noroeste. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química del Noroeste; ArgentinaFil: Schiewer, Christine. Universität Göttingen; AlemaniaFil: Schober, Anne. Universität Göttingen; AlemaniaFil: Dechert, Sebastian. Universität Göttingen; AlemaniaFil: Siewert, Inke. Universität Göttingen; AlemaniaFil: Meyer, Franc. Universität Göttingen; Alemani
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