Coordination and organometallic precursors of group 10 and 11 Focused electron beam induced deposition of metals and insight gained from chemical vapour deposition, atomic layer deposition, and fundamental surface and gas phase studies

Nanostructured materials made from group 10 Ni, Pd, Pt and group 11 Cu, Ag, Au elements have outstanding technological relevance in microelectronics, nano optics, catalysis, and energy conversion. Processes that allow for the easy and reliable fabrication of such nanostructures are heavily sought after. Focused electron beam induced deposition FEBID is the only direct write technique that can fabricate nanostructures with arbitrary shape and dimensions down to the sub 10 nm regime. However, the complex chemistry of FEBID involving electron induced dissociation processes of metalorganic precursors molecules, surface kinetics, and thermal effects is poorly understood and far from being optimized. Here, we review in a comparative manner the performance and the underlying chemical reactions of surface deposition processes, namely, chemical vapour deposition CVD , atomic layer deposition ALD , and FEBID itself. The knowledge gained in CVD and ALD as related surface deposition techniques will help us to understand the spatially selective chemistry occurring in FEBID. Fundamental surface and gas phase studies provide insight to electron induced chemistry and desorption of precursor fragments. Specific emphasis is put on the type of the ligands and their different behaviour under thermal, surface related, and electron induced processes. The comprehensive overview of the current state of FEBID for group 10 and 11 metals includes reactive environments and purification approaches as these may provide valuable information on the design of novel precursors. The evaluation of the precursor and process performance is extended to include W, Co, Fe, Ru, Rh, and Ir to represent a general guide towards future developments in FEBID. These may not only rely on the design of novel compounds but also on optimized deposition strategies inspired by ALD and CV

Project #37: Management Guidelines for Patients with COVID-19: Rapid Cycle Improvement

Project’s purpose is to rapidly devise, continually improve, educate, and implement a live and changing COVID-19 management guideline based upon emerging best available evidence. This project also aims to optimize the care of patients with COVID-19 and improve patient outcomes.https://scholarlycommons.henryford.com/qualityexpo2022/1004/thumbnail.jp

Transcendental-Phenomenological Proof and Descriptive Metaphysics

Following P.F. Strawson's reading of Kant, the majority of the literature on transcendental arguments seeks to divorce such arguments from their original Kantian context. This thesis is concerned with Mark Sacks's recent defence of transcendental arguments, which takes a different approach. A critique is given of Sacks's work and extensions and modifications of his approach are recommended. It is proposed that certain difficulties encountered by Kant's transcendentally-ideal approach can be overcome with Hegelian solutions

Enzyme Promiscuity in Enolase Superfamily. Theoretical Study of o-Succinylbenzoate Synthase Using QM/MM Methods

The promiscuous activity of the enzyme o-succinylbenzoate synthase (OSBS) from the actinobacteria Amycolatopsis is investigated by means of QM/MM methods, using both density functional theory and semiempirical Hamiltonians. This enzyme catalyzes not only the dehydration of 2-succinyl-6R-hydroxy-2,4-cyclohexadiene-1R-carboxylate but also catalyzes racemization of different acylamino acids, with N-succinyl-R-phenylglycine being the best substrate. We investigated the molecular mechanisms for both reactions exploring the potential energy surface. Then, molecular dynamics simulations were performed to obtain the free energy profiles and the averaged interaction energies of enzymatic residues with the reacting system. Our results confirm the plausibility of the reaction mechanisms proposed in the literature, with a good agreement between theoretical and experimentally derived activation free energies. Our simulations unravel the role played by the different residues in each of the two possible reactions. The presence of flexible loops in the active site and the selection of structural modifications in the substrate seem to be key elements to promote the promiscuity of this enzyme.This work was supported by the Spanish Ministerio de Economia y Competitividad project CTQ2012-36253-C03-03 ́ and FEDER funds. K.S. thanks the Polish National Science Center (NCN) for Grant 2011/02/A/ST4/00246. The authors acknowledge computational facilities of the Servei d’Informatica ̀ de la Universitat de Valencia in the ̀ “Tirant” supercomputer, which is part of the Spanish Supercomputing Network

Electron-induced modifications in thin solid films of nitromethane-D

The effect of electron exposure at an incident energy of 10.5 eV on solid molecular multilayer films containing nitromethane-D3 has been studied by high-resolution electron-energy-loss (HREEL) spectroscopy. Nitromethane-D3 was mixed with varying amounts of hexane or heptane to investigate whether the hydrocarbon component or, more specifically, resonant H- production which is known to occur at electron energies around 10 eV plays a role in electron-induced modifications of the nitro group. While bands related to vibrations of the nitro group clearly diminish under exposure, the rate of this process does not depend on the amount of the admixed hydrocarbon component. Consequently, the hydrocarbon component and thus also the H- producing resonance around 10 eV do not determine the rate of modification of nitromethane-D3 at the investigated energy

Theoretische und spektroskopische Untersuchungen zu den Triplettzustaenden aromatischer Kohlenwasserstoffe

Available from TIB Hannover: DW 4321 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Electron induced dissociation in the condensed-phase nitromethane: II. Desorption of neurtral fragments

Low energy electron induced dissociation in multilayer films of nitromethane (CD3NO2) was investigated by high resolution electron energy loss spectroscopy (HREELS) and by the electron stimulated desorption (ESD) of neutral species. HREELS measurements show that the lowest electronic states of the condensed molecule are very similar to those seen in the gas phase. Desorbed neutrals were detected using combined non-resonant multi-photon ionization at 355 nm and time of flight mass spectrometry. The most intense signals detected were those of CD3 + and NO + and are attributed primarily to the desorption of CD3 and NO2 fragments following molecular dissociation via low-lying electronic excited states of nitromethane (the detected NO + being the result of the dissociative ionization of NO2). By varying the time delay between the incident electron pulse and the ionizing laser pulse, it is possible to measure the kinetic energy distributions of desorbing fragments. The kinetic energy distributions above ~ 5 eV appear invariant with incident electron energy, indicating that the same desorption process (dissociation via low-lying electronic states) operates at all the studied incident energies. Nevertheless, measurements of neutral yields as functions of incident electron energy demonstrate that excitation of the dissociative electronic states also proceeds via previously identified transient negative ions. At energies less than ~ 5 eV, contributions from dissociative electron attachment are also observed in the yield of CD3 and other neutral fragments