Summaries of FY 1990 Research in the Chemical Sciences
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Depa1'tment of Physical Chemistry Isl'ael
.. ANNUAL PROGRESS REPORT C00-3221-67 (For the period September 79 - July 80) Under Contract No. DOE/EV/03221 on THE NATURE OF OXYGEN CONTAINING RADICALS IN RADIATION CHEMISTRY AND PHOTOCHEMISTRY OF AQUEOUS SOLUTIONS Submitted by PROFESSOR GIDON CZAPSKI Depa1'tment of Physical Chemistry The Hebl'eW Univel'sity~ Jerusalem~ Isl'ael IJISTRIBUTIOJI OF THIS DOCUMENT IS UNUMITEJJ DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency Thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. ANNUAL PROGRESS REPORT C00-3221-67 (For the period September 79 - July 80) Und~r Contract No. DOE/EV/03221·· on THE NATURE OF OXYGEN CONTAINING RADICALS IN RADIATION CHEMISTRY AND PHOTOCHEMISTRY OF AQUEOUS SOLUTIONS Submitted by PROFESSOR GIDON CZAPSKI lh~s book was ~repared as an account of work sponsored by an agency of the United States Government :!:~; the ~~•ted Stat~ ~nment nor any agency thereof, nor any of their employees, makes an~ v. -
Effects of Metal Contacts and Doping for High
TW-P061 Effects of metal contacts and doping for high-performance field-effect transistor based on tungsten diselenide (WSe2) Seo-Hyeon Jo and Jin-Hong Park School of Electronics and Electrical Engineering, Sungkyunkwan University, Suwon 440-746, Korea Transition metal dichalcogenides (TMDs) with two-dimensional layered structure, such as molybdenum disulfide (MoS2) and tungsten diselenide (WSe2), are considered attractive materials for future semiconductor devices due to its relatively superior electrical, optical, and mechanical properties. Their excellent scalability down to a monolayer based on the van der Waals layered structure without surface dangling bonds makes semiconductor devices based on TMD free from short channel effect. In comparison to the widely studied transistor based on MoS2, researchs focusing on WSe2 transistor are still limited. WSe2 is more resistant to oxidation in humid ambient condition and relatively air-stable than sulphides such as MoS2. These properties of WSe2 provide potential to fabricate high-performance filed-effect transistor if outstanding electronic characteristics can be achieved by suitable metal contacts and doping phenomenon. Here, we demonstrate the effect of two different metal contacts (titanium and platinum) in field-effect transistor based on WSe2, which regulate electronic characteristics of device by controlling the effective barreier height of the metal-semiconductor junction. Electronic properties of WSe2 transistor were systematically investigated through monitoring of threshold voltage shift, carrier concentration difference, on-current ratio, and field-effect mobility ratio with two different metal contacts. Additionally, performance of transistor based on WSe2 is further enhanced through reliable and controllable n-type doping method of WSe2 by triphenylphosphine (PPh3), which activates the doping phenomenon by thermal annealing process and adjust the doping level by controlling the doping concentration of PPh3. -
Proton-Coupled Reduction of N2 Facilitated by Molecular Fe Complexes
Proton-Coupled Reduction of N2 Facilitated by Molecular Fe Complexes Thesis by Jonathan Rittle In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy CALIFORNIA INSTITUTE OF TECHNOLOGY Pasadena, California 2016 (Defended November 9, 2015) ii 2016 Jonathan Rittle All Rights Reserved iii ACKNOWLEDGEMENTS My epochal experience in graduate school has been marked by hard work, intellectual growth, and no shortage of deadlines. These facts leave little opportunity for an acknowledgement of those whose efforts were indispensable to my progress and perseverance, and are therefore disclosed here. First and foremost, I would like to thank my advisor, Jonas Peters, for his tireless efforts in molding me into the scientist that I am today. His scientific rigor has constantly challenged me to strive for excellence and I am grateful for the knowledge and guidance he has provided. Jonas has given me the freedom to pursue scientific research of my choosing and shown a remarkable degree of patience while dealing with my belligerent tendencies. Perhaps equally important, Jonas has built a research group that is perpetually filled with the best students and postdoctoral scholars. Their contributions to my graduate experience are immeasurable and I wish them all the best of luck in their future activities. In particular, John Anderson, Dan Suess, and Ayumi Takaoka were senior graduate students who took me under their wings when I joined the lab as a naïve first-year graduate student. I am grateful for the time and effort that they collectively spent in teaching me the art of chemical synthesis and for our unforgettable experiences outside of lab. -
Structural and Electronic Influences on Phosphite Basicity and Its Application to Heterogeneous and Homogeneous Catalysis David Evan Schiff Iowa State University
Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1983 Structural and electronic influences on phosphite basicity and its application to heterogeneous and homogeneous catalysis David Evan Schiff Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Inorganic Chemistry Commons Recommended Citation Schiff, David Evan, "Structural and electronic influences on phosphite basicity and its application to heterogeneous and homogeneous catalysis " (1983). Retrospective Theses and Dissertations. 8960. https://lib.dr.iastate.edu/rtd/8960 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. INFORMATION TO USERS This reproduction was made from a copy of a document sent to us for microfilming. While the most advanced technology has been used to photograph and reproduce this document, the quality of the reproduction is heavily dependent upon the quality of the material submitted. The following explanation of techniques is provided to help clarify markings or notations which may appear on this reproduction. 1.The sign or "target" for pages apparently lacking from the document photographed is "Missing Page(s)". If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting through an image and duplicating adjacent pages to assure complete continuity. -
A Photoionization Reflectron Time‐Of‐Flight Mass Spectrometric
Articles ChemPhysChem doi.org/10.1002/cphc.202100064 A Photoionization Reflectron Time-of-Flight Mass Spectrometric Study on the Detection of Ethynamine (HCCNH2) and 2H-Azirine (c-H2CCHN) Andrew M. Turner,[a, b] Sankhabrata Chandra,[a, b] Ryan C. Fortenberry,*[c] and Ralf I. Kaiser*[a, b] Ices of acetylene (C2H2) and ammonia (NH3) were irradiated with 9.80 eV, and 10.49 eV were utilized to discriminate isomers energetic electrons to simulate interstellar ices processed by based on their known ionization energies. Results indicate the galactic cosmic rays in order to investigate the formation of formation of ethynamine (HCCNH2) and 2H-azirine (c-H2CCHN) C2H3N isomers. Supported by quantum chemical calculations, in the irradiated C2H2:NH3 ices, and the energetics of their experiments detected product molecules as they sublime from formation mechanisms are discussed. These findings suggest the ices using photoionization reflectron time-of-flight mass that these two isomers can form in interstellar ices and, upon spectrometry (PI-ReTOF-MS). Isotopically-labeled ices confirmed sublimation during the hot core phase, could be detected using the C2H3N assignments while photon energies of 8.81 eV, radio astronomy. 1. Introduction acetonitrile (CH3CN; 1) and methyl isocyanide (CH3NC; 2) ‘isomer doublet’ (Figure 2) – the methyl-substituted counterparts of For the last decade, the elucidation of the fundamental reaction hydrogen cyanide (HCN) and hydrogen isocyanide (HNC) – has pathways leading to structural isomers – molecules with the been detected toward the star-forming region SgrB2.[4,8–9] same molecular formula, but distinct connectivities of atoms – However, none of their higher energy isomers has ever been of complex organic molecules (COMs) in the interstellar identified in any astronomical environment: 2H-azirine (c- [10–14] [15–19] medium (ISM) has received considerable interest from the NCHCH2; 3), ethynamine (HCCNH2; 4), ketenimine [1–3] [20] [21] astrochemistry and physical chemistry communities. -
A Study of Organosilicon Free Radicals Jay Stephen Curtice Iowa State College
Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1954 A study of organosilicon free radicals Jay Stephen Curtice Iowa State College Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Organic Chemistry Commons, and the Physical Chemistry Commons Recommended Citation Curtice, Jay Stephen, "A study of organosilicon free radicals " (1954). Retrospective Theses and Dissertations. 13411. https://lib.dr.iastate.edu/rtd/13411 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. A STUDY OF ORGANOSILICON FREE RADICALS by Jay Stephen Curtice A Dissertation Sul»nitted to the Graduate Faculty in Partial Fulfillment of The Requirements for the Degree of DOCTOR OF PHILOSOPHY Major Subject: Physical Organic Chemistry Approved; Signature was redacted for privacy. Signature was redacted for privacy. In CJiiarge of Major Work Signature was redacted for privacy. Head of Major DepartMnt Signature was redacted for privacy. Dean of Graduate College Iowa State College 195^ UMI Number: DP12662 INFORMATION TO USERS The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleed-through, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. -
Formation of Fulvene in the Reaction of C2H with 1,3-Butadiene
UC Berkeley UC Berkeley Previously Published Works Title Formation of fulvene in the reaction of C2H with 1,3-butadiene Permalink https://escholarship.org/uc/item/34x2s372 Authors Lockyear, JF Fournier, M Sims, IR et al. Publication Date 2015-02-15 DOI 10.1016/j.ijms.2014.08.025 Peer reviewed eScholarship.org Powered by the California Digital Library University of California International Journal of Mass Spectrometry 378 (2015) 232–245 Contents lists available at ScienceDirect International Journal of Mass Spectrometry journal homepage: www.elsevier.com/locate/ijms Formation of fulvene in the reaction of C2H with 1,3-butadiene Jessica F. Lockyear a,1, Martin Fournier b,c, Ian R. Sims b, Jean-Claude Guillemin c, Craig A. Taatjes d, David L. Osborn d, Stephen R. Leone a,* a Departments of Chemistry and Physics, University of California at Berkeley, and Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA b Institut de Physique de Rennes, UMR CNRS-UR1 6251, Université de Rennes 1, 263 Avenue du Général Leclerc, 35042 Rennes CEDEX,France c Ecole Nationale Supérieure de Chimie de Rennes, CNRS UMR 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes CEDEX 7, France d Combustion Research Facility, Mailstop 9055, Sandia National Laboratories, Livermore, CA 94551-0969, USA ARTICLE INFO ABSTRACT Article history: Products formed in the reaction of C2H radicals with 1,3-butadiene at 4 Torr and 298 K are probed using Received 30 May 2014 photoionization time-of-flight mass spectrometry. The reaction takes place in a slow-flow reactor, and Received in revised form 21 July 2014 products are ionized by tunable vacuum-ultraviolet light from the Advanced Light Source. -
A Chemical Kinetics Network for Lightning and Life in Planetary Atmospheres P
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by St Andrews Research Repository The Astrophysical Journal Supplement Series, 224:9 (33pp), 2016 May doi:10.3847/0067-0049/224/1/9 © 2016. The American Astronomical Society. All rights reserved. A CHEMICAL KINETICS NETWORK FOR LIGHTNING AND LIFE IN PLANETARY ATMOSPHERES P. B. Rimmer and Ch Helling School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, UK; [email protected] Received 2015 June 3; accepted 2015 October 22; published 2016 May 23 ABSTRACT There are many open questions about prebiotic chemistry in both planetary and exoplanetary environments. The increasing number of known exoplanets and other ultra-cool, substellar objects has propelled the desire to detect life andprebiotic chemistry outside the solar system. We present an ion–neutral chemical network constructed from scratch, STAND2015, that treats hydrogen, nitrogen, carbon, and oxygen chemistry accurately within a temperature range between 100 and 30,000 K. Formation pathways for glycine and other organic molecules are included. The network is complete up to H6C2N2O3. STAND2015 is successfully tested against atmospheric chemistry models for HD 209458b, Jupiter, and the present-day Earth using a simple one- dimensionalphotochemistry/diffusion code. Our results for the early Earth agree with those of Kasting for CO2,H2, CO, and O2, but do not agree for water and atomic oxygen. We use the network to simulate an experiment where varied chemical initial conditions are irradiated by UV light. The result from our simulation is that more glycine is produced when more ammonia and methane is present. -
Synthesis of Phosphine-Functionalized Metal
DISS. ETH NO. 23507 Understanding and improving gold-catalyzed formic acid decomposition for application in the SCR process A thesis submitted to attain the degree of DOCTOR OF SCIENCES of ETH ZURICH (Dr. sc. ETH Zurich) presented by MANASA SRIDHAR M. Sc. in Chemical Engineering, University of Cincinnati born on 12.12.1987 citizen of India accepted on the recommendation of Prof. Dr. Jeroen A. van Bokhoven, examiner Prof. Dr. Oliver Kröcher, co-examiner Prof. Dr. Christoph Müller, co-examiner 2016 “anything can happen, in spite of what you’re pretty sure should happen.” Richard Feynman Table of content Abstract .............................................................................................................................. II die Zusammenfassung ..................................................................................................... VI Chapter 1 Introduction .......................................................................................................... 1 Chapter 2 Methods ............................................................................................................ 15 Chapter 3 Unique selectivity of Au/TiO2 for ammonium formate decomposition under SCR- relevant conditions ............................................................................................................. 25 Chapter 4 Effect of ammonia on the decomposition of ammonium formate and formic acid on Au/TiO2 ............................................................................................................................. -
Hydrogen Isocyanide, HNC, in Titan's Ionosphere
EPSC Abstracts Vol. 8, EPSC2013-589, 2013 European Planetary Science Congress 2013 EEuropeaPn PlanetarSy Science CCongress c Author(s) 2013 Hydrogen isocyanide, HNC, in Titan’s ionosphere V. Vuitton (1), R. V. Yelle (2), S. J. Klippenstein (3), P. Lavvas (4), S. M. Hörst (5) and A. Bazin (1) (1) IPAG, UMR CNRS 5274, Université Joseph Fourier Grenoble 1, France, (2) LPL, University of Arizona, Tucson AZ, USA, (3) Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne IL, USA, (4) GSMA, UMR CNRS 6089, Université de Reims Champagne-Ardenne, France, (5) CIRES, University of Colorado, Boulder CO, USA ([email protected]) to a lesser extent from N(4S) + CH HNC + H. It Abstract 2 → is mainly destroyed by its reaction with N(2D) above The first identification of hydrogen isocyanide, HNC, 1000 km and H at lower altitude. The column density 13 2 in Titan’s atmosphere has recently been reported. Us- obtained is 3.4 10 cm− , which is about 3 times × ing a coupled ion-neutral photochemical model, we higher than the value derived from the observations. It find that both neutral and ion chemistry contribute to is argued that this discrepancy can be explained by the the production and loss of HNC. According to our cal- poor knowledge of three key reactions: H + HNC 6 2 → culations, the HNC density reaches a peak of 10 H + HCN, H + H2CN HNC/HCN + H2 and N( D) 3 ∼ → cm− at an altitude of 950-1000 km. This translates + HNC CN2 + H / CH + N2. 13 2 → into a a column density of 1.8 10 cm− above 800 × km, in fair agreement with the observations. -
Hydrogen Sulfide Inhibits Oxidative Stress in Lungs from Allergic Mice in Vivo
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector European Journal of Pharmacology 698 (2013) 463–469 Contents lists available at SciVerse ScienceDirect European Journal of Pharmacology journal homepage: www.elsevier.com/locate/ejphar Immunopharmacology and Inflammation Hydrogen sulfide inhibits oxidative stress in lungs from allergic mice in vivo Leticia R. Benetti a,1, Daiana Campos a,1, Sonia A. Gurgueira b, Anibal E. Vercesi b, Cristiane E.V. Guedes a, Kleber L. Santos a, John L. Wallace c, Simone A. Teixeira d, Juliana Florenzano d, Soraia K.P. Costa d, Marcelo N. Muscara´ d, Heloisa H.A. Ferreira a,n a Laboratory of Inflammation Research, Sao~ Francisco University, Braganc-a Paulista, Sao~ Paulo 12 916 900, Brazil b Laboratory of Bioenergetics, Department of Clinical Pathology, Faculty of Medical Sciences, State University of Campinas, Campinas, Sao~ Paulo 12 916 900, Brazil c Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada d Department. of Pharmacology, Institute of Biomedical Sciences, University of Sao~ Paulo, Sao~ Paulo 12 916 900, Brazil article info abstract Article history: Recent studies show that endogenous hydrogen sulfide (H2S) plays an anti-inflammatory role in the Received 20 August 2012 pathogenesis of airway inflammation. This study investigated whether exogenous H2S may counteract Received in revised form oxidative stress-mediated lung damage in allergic mice. Female BALB/c mice previously sensitized -
High Energy Radical Chemistry Formation of HCN-Rich
www.nature.com/scientificreports Correction: Author Correction OPEN High Energy Radical Chemistry Formation of HCN-rich Atmospheres on early Earth Received: 9 February 2017 Martin Ferus1, Petr Kubelík1,2, Antonín Knížek1, Adam Pastorek1, John Sutherland3 & Accepted: 13 June 2017 Svatopluk Civiš1 Published: xx xx xxxx Recent results in prebiotic chemistry implicate hydrogen cyanide (HCN) as the source of carbon and nitrogen for the synthesis of nucleotide, amino acid and lipid building blocks. HCN can be produced during impact events by reprocessing of carbonaceous and nitrogenous materials from both the impactor and the atmosphere; it can also be produced from these materials by electrical discharge. Here we investigate the efect of high energy events on a range of starting mixtures representative of various atmosphere-impactor volatile combinations. Using continuously scanning time–resolved spectrometry, we have detected ·CN radical and excited CO as the initially most abundant products. Cyano radicals and excited carbon monoxide molecules in particular are reactive, energy-rich species, but are resilient owing to favourable Franck–Condon factors. The subsequent reactions of these frst formed excited species lead to the production of ground-state prebiotic building blocks, principally HCN. During the frst sixteen years of the 21st century, major progress in the synthesis of biological molecules under prebiotically plausible conditions has been reported1–6. Hydrogen cyanide (HCN) and its hydration product 5–10 formamide (HCONH2) are central to such syntheses . HCN exhibits many properties that make it an ideal building block, but above all it is a high energy compound – because of its triple bond – which has a propensity to form when organic matter is bombarded with excess energy11.