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Time-resolved Spectroelectrochemical Investigation of Organic Mixed Conductors
Get PDFOrganic mixed ionic and electronic conductors (OMIECs) are an emerging class of materials that have been applied for a wide range of electrochemical applications. Due to the complexity inherent to the ionic-electroniccoupling, understanding the underlying mechanisms involved in the OMIEC operation is an exciting and very lively research field. In this work, we highlight the use of time-resolved Vis-NIR spectroelectrochemistry tocharacterize these materials. We discuss an example, where we show that by combining this tool with spectraldecomposition, we are able to understand fundamental aspects of the doping in an OMIEC film. The methodswe present here can be generalized and used to characterize any electrochromic material
Tuning NaCo(II) Bimetallic Cooperativity to Perform Co–H Exchange / C–F Bond Activation Processes in Polyfluoroarenes
Get PDFRecent advances in cooperative chemistry have shown the potential of heterobimetallic complexes combining an alkali-metal with an earth abundant divalent transition metal for the functionalisation of synthetically relevant aromatic molecules via deprotonative metalation. Pairing sodium with cobalt (II), here we provide an overview of the reactivity of bimetallic [NaCo(HMDS)3] [HMDS = N(SiMe3)2] towards C-H and C-F functionalisation of a wide range of perfluorinated molecules. These studies also uncover the enormous potential of this heterobimetallic base to perform Co-H exchanges with excellent selectivity and exceptional stoichiometric control as well as shedding light on the key role played by the alkali-metal
Northwest to Southwest – The Conference Reports of the 5th and 6th Swiss Symposium in Point-of-Care Diagnostics held in Muttenz 2022 and Sion 2023
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Operando X-ray Absorption Spectroscopy as a Powerful Tool for Uncovering Property-Activity Relationships for Oxygen Evolution Transition Metal Oxide Catalysts
Get PDFThe development of a sustainable and environmentally friendly energy economy encompasses efficient hydrogen production from renewable energy via electrolysis. In this context, great efforts have recently been dedicated to the development of more efficient and cost-effective electrocatalysts. Understanding the mechanism of the oxygen evolution reaction (OER) on transition metal oxide catalysts is of great interest, but the reaction and system complexity render the characterization of active sites and the understanding of reaction mechanisms challenging. Time resolved Quick X-ray Absorption Spectroscopy (XAS) can provide dynamic snapshots of the electronic and local structure of nanocatalysts, revealing the ‘real active phase’ of the catalyst, which can substantially differ from the as-prepared catalyst powder or the catalyst in form of an electrode under non-operating conditions. In this contribution, several examples will be presented showing how operando XAS can reveal catalyst-support interactions, changes in the reaction mechanism, and dynamic reversible/irreversible changes in the electronic and local structure of OER catalysts
The Chemistry of Atmospheric Aerosols: At the Nexus Between Climate, Energy, and Air Quality
Get PDFAtmospheric aerosols can be emitted directly as particles or formed in the atmosphere from phase transitions of gaseous compounds with low enough vapor pressure. During their lifecycle in the atmosphere, aerosols undergo multiphase changes, altering chemical composition, reactivity, physical and optical properties, ultimately influencing how they impact climate, human health and ecosystems. The understanding of the chemical processes in the atmosphere is crucial to assess these effects. Here we provide a brief overview on relevant aerosol chemical processes and measurement techniques with no claim to completeness and describe the Swiss contribution to the European infrastructure ACTRIS for long-term monitoring and its relevance for the research field
Localization of Disulfide Bonds in Ribonuclease Using Low pH Trypsin and LC-ESI-QTOF-MS: FH-HES (Universities of Applied Sciences)
No full textWe evaluated a method to localize disulfide bonds in bovine pancreatic ribonuclease (RNase) by applying low pH trypsin protein digestion with a bottom-up LC-ESI-QTOF-MS approach. The goal was to minimize disulfide bond scrambling during sample preparation. By using N-ethylmaleimide (NEM) for alkylation of free cysteines, we achieved 92% sequence coverage and successfully identified the native disulfide bonds between specific cysteine residues. However, scrambled disulfide bonds were also observed. Our results indicate that while this low pH digestion method helps preserve native disulfide bonds, further refinement is needed to fully prevent disulfide bond rearrangement during sample preparation