Performance of a Nonempirical Density Functional on Molecules and Hydrogen-Bonded Complexes
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Studies on Dimethylsilylene James Bailey Kimble III Iowa State University
Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1977 Studies on dimethylsilylene James Bailey Kimble III Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Organic Chemistry Commons Recommended Citation Kimble, James Bailey III, "Studies on dimethylsilylene " (1977). Retrospective Theses and Dissertations. 7566. https://lib.dr.iastate.edu/rtd/7566 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 material was produced from a microfilm copy of the original document. While the most advanced technological means to photograph and reproduce this document have been used, the quality is heavily dependent upon the quality of the original submitted. The following explanation of techniques is provided to help you understand markings or patterns 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 thru an image and duplicating adjacent pages to insure you complete continuity. 2. When an image on the film is obliterated with a large round black mark, it is an indication that the photographer suspected that the copy may have moved during exposure and thus cause a blurred image. -
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. -
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. -
Directed Gas Phase Formation of Silicon Dioxide and Implications for the Formation of Interstellar Silicates
ARTICLE DOI: 10.1038/s41467-018-03172-5 OPEN Directed gas phase formation of silicon dioxide and implications for the formation of interstellar silicates Tao Yang 1,2, Aaron M. Thomas1, Beni B. Dangi1,3, Ralf I. Kaiser 1, Alexander M. Mebel 4 & Tom J. Millar 5 1234567890():,; Interstellar silicates play a key role in star formation and in the origin of solar systems, but their synthetic routes have remained largely elusive so far. Here we demonstrate in a combined crossed molecular beam and computational study that silicon dioxide (SiO2) along with silicon monoxide (SiO) can be synthesized via the reaction of the silylidyne radical (SiH) with molecular oxygen (O2) under single collision conditions. This mechanism may provide a low-temperature path—in addition to high-temperature routes to silicon oxides in circum- stellar envelopes—possibly enabling the formation and growth of silicates in the interstellar medium necessary to offset the fast silicate destruction. 1 Department of Chemistry, University of Hawai’iatMānoa, Honolulu, HI 96822, USA. 2 State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200062, China. 3 Department of Chemistry, Florida Agricultural and Mechanical University, Tallahassee, FL 32307, USA. 4 Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA. 5 Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast, Belfast, BT7 1NN, UK. Correspondence and requests for materials should be addressed to R.I.K. (email: [email protected]) or to A.M.M. (email: mebela@fiu.edu) or to T.J.M. (email: [email protected]) NATURE COMMUNICATIONS | (2018) 9:774 | DOI: 10.1038/s41467-018-03172-5 | www.nature.com/naturecommunications 1 ARTICLE NATURE COMMUNICATIONS | DOI: 10.1038/s41467-018-03172-5 — 28 + 28 + he origin of interstellar silicate grains nanoparticles ( SiO2 ), and 44 ( SiO ). -
Product Detection of the CH Radical Reactions with Ammonia and Methyl-Substituted Amines Jérémy Bourgalais, Kacee L
Product Detection of the CH Radical Reactions with Ammonia and Methyl-Substituted Amines Jérémy Bourgalais, Kacee L. Caster, Olivier Durif, David L. Osborn, Sébastien D. Le Picard, Fabien Goulay To cite this version: Jérémy Bourgalais, Kacee L. Caster, Olivier Durif, David L. Osborn, Sébastien D. Le Picard, et al.. Product Detection of the CH Radical Reactions with Ammonia and Methyl-Substituted Amines. Journal of Physical Chemistry A, American Chemical Society, 2019, 123 (11), pp.2178-2193. 10.1021/acs.jpca.8b11688. hal-02089225 HAL Id: hal-02089225 https://hal-univ-rennes1.archives-ouvertes.fr/hal-02089225 Submitted on 11 Apr 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Page 1 of 47 The Journal of Physical Chemistry 1 2 3 Product Detection of the CH Radical Reactions with Ammonia and 4 5 6 Methyl-Substituted Amines 7 8 1 2 3 4 9 Jeremy Bourgalais, Kacee L. Caster, Olivier Durif, David L. Osborn, Sebastien D. Le 10 11 Picard,3 and Fabien Goulay2,* 12 13 1 LATMOS/IPSL, UVSQ Université Paris-Saclay, Sorbonne Université, CNRS, Guyancourt, 14 -
House Fly Attractants and Arrestante: Screening of Chemicals Possessing Cyanide, Thiocyanate, Or Isothiocyanate Radicals
House Fly Attractants and Arrestante: Screening of Chemicals Possessing Cyanide, Thiocyanate, or Isothiocyanate Radicals Agriculture Handbook No. 403 Agricultural Research Service UNITED STATES DEPARTMENT OF AGRICULTURE Contents Page Methods 1 Results and discussion 3 Thiocyanic acid esters 8 Straight-chain nitriles 10 Propionitrile derivatives 10 Conclusions 24 Summary 25 Literature cited 26 This publication reports research involving pesticides. It does not contain recommendations for their use, nor does it imply that the uses discussed here have been registered. All uses of pesticides must be registered by appropriate State and Federal agencies before they can be recommended. CAUTION: Pesticides can be injurious to humans, domestic animals, desirable plants, and fish or other wildlife—if they are not handled or applied properly. Use all pesticides selectively and carefully. Follow recommended practices for the disposal of surplus pesticides and pesticide containers. ¿/áepé4áaUÁí^a¡eé —' ■ -"" TMK LABIL Mention of a proprietary product in this publication does not constitute a guarantee or warranty by the U.S. Department of Agriculture over other products not mentioned. Washington, D.C. Issued July 1971 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price 25 cents House Fly Attractants and Arrestants: Screening of Chemicals Possessing Cyanide, Thiocyanate, or Isothiocyanate Radicals BY M. S. MAYER, Entomology Research Division, Agricultural Research Service ^ Few chemicals possessing cyanide (-CN), thio- cyanate was slightly attractive to Musca domes- eyanate (-SCN), or isothiocyanate (~NCS) radi- tica, but it was considered to be one of the better cals have been tested as attractants for the house repellents for Phormia regina (Meigen). -
Aromatic Formation Promoted by Ion-Driven Radical Pathways In
Aromatic Formation Promoted by Ion-Driven Radical Pathways in EUV Photochemical Experiments Simulating Titan’s Atmospheric Chemistry Jérémy Bourgalais, Nathalie Carrasco, Ludovic Vettier, Antoine Comby, Dominique Descamps, Stephane Petit, Valérie Blanchet, Jerôme Gaudin, Yann Mairesse, Bernard Marty To cite this version: Jérémy Bourgalais, Nathalie Carrasco, Ludovic Vettier, Antoine Comby, Dominique Descamps, et al.. Aromatic Formation Promoted by Ion-Driven Radical Pathways in EUV Photochemical Experiments Simulating Titan’s Atmospheric Chemistry. Journal of Physical Chemistry A, American Chemical Society, 2021, 125 (15), pp.3159-3168. 10.1021/acs.jpca.1c00324. insu-03201041 HAL Id: insu-03201041 https://hal-insu.archives-ouvertes.fr/insu-03201041 Submitted on 18 May 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Aromatic Formation Promoted by Ion-Driven Radical Pathways in EUV Photochemical Experiments Simulating Titan's Atmospheric Chemistry J´er´emyBourgalais,∗,y,z,k Nathalie Carrasco,y Ludovic Vettier,y Antoine Comby,{ Dominique Descamps,{ -
Reaction of Allyl Radical with Acetylene
石 油 学 会 誌 J. Japan Petrol. Inst., 23, (2), 133-138 (1980) 133 Reaction of Allyl Radical with Acetylene Daisuke NOHARA* and Tomoya SAKAI* The title reaction was performed at 580-740℃, employing biallyl as the source of the allyl radical. The main product of addition of allyl radical to acetylene was cyclopentadiene, and the selectivity attained was more than 90 percent of the total C5 products. Such acyclic product as 1,4-pentadiene was scarcely formed in distinct contrast with the result of the addition of allyl radical to ethylene, in which almost equal amounts of 1-pentene and cyclopentene were formed. The product distribution of the title reaction was reported, and a scheme for the product forma- tion was proposed. From the kinetic analysis, the overall activation energy of reaction for the formation of cyclopentadiene from allyl radical and acetylene was estimated. The present experiment on thermal reaction of 1. Introduction biallyl with acetylene was undertaken to examine Allyl radical has been suggested as playing the the possibility of cycloaddition of allyl radical to role of diene1) in the cyclization reaction with the triple bond. Cyclopentadiene, one of the ex- olefins to form C5-cyclic products analogous to pected C5 compounds in the present reaction, was butadiene which thermally combines with olefins formed in high selectivity, i.e., ca. 40 percent of to yield C6-cyclic compounds. In the pyrolysis all products, including the products from the thermal of ethylene2), C6-cyclic compounds were formed reaction of acetylene itself. The selectivity was mostly through the Diels-Alder reaction between formed to be as high as 60 percent, excluding the butadiene and ethylene, the butadiene being one products from the reaction of acetylene itself. -
Microhydration and the Enhanced Acidity of Free Radicals
molecules Article Microhydration and the Enhanced Acidity of Free Radicals John C. Walton EaStCHEM School of Chemistry, University of St. Andrews, St. Andrews KY16 9ST, UK; [email protected]; Tel.: +44-(0)1334-463864 Received: 31 January 2018; Accepted: 14 February 2018; Published: 14 February 2018 Abstract: Recent theoretical research employing a continuum solvent model predicted that radical centers would enhance the acidity (RED-shift) of certain proton-donor molecules. Microhydration studies employing a DFT method are reported here with the aim of establishing the effect of the solvent micro-structure on the acidity of radicals with and without RED-shifts. Microhydration cluster structures were obtained for carboxyl, carboxy-ethynyl, carboxy-methyl, and hydroperoxyl radicals. The numbers of water molecules needed to induce spontaneous ionization were determined. The hydration clusters formed primarily round the CO2 units of the carboxylate-containing radicals. Only 4 or 5 water molecules were needed to induce ionization of carboxyl and carboxy-ethynyl radicals, thus corroborating their large RED-shifts. Keywords: free radicals; acidity; DFT computations; hydration 1. Introduction A transient-free radical is necessarily reactive at the site (X) of its unpaired electron (upe). In addition, a free radical with a structure containing a proton donor group may undergo ionic dissociation to a radical anion and a proton: • • − + XH2WAH! XH2WA + H in which W is a connector or spacer group, and A is the site of the departing proton. Effectively, the free radicals in this category can function as Br'nsted acids. More than 40 years ago, Hayon and Simic drew attention to the fact that free radicals could be more acidic than parent compounds [1]. -
Synthesis, Structure and Reactivity of Neutral Hydrogen-Substituted
5082 Organometallics 2009, 28, 5082–5089 DOI: 10.1021/om900348m Synthesis, Structure, and Reactivity of Neutral Hydrogen-Substituted Ruthenium Silylene and Germylene Complexes Paul G. Hayes,† Rory Waterman,‡ Paul B. Glaser,§ and T. Don Tilley* Department of Chemistry, University of California, Berkeley, California 94720-1460. †Current address: Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta, Canada, T1K 3M4. ‡ Current address: Department of Chemistry, University of Vermont, Burlington, Vermont 05405. §Current address: General Electric Global Research, Niskayuna, NY 12309. Received May 3, 2009 i Reaction of Cp*( Pr2MeP)RuCl (1) with 0.5 equiv of Mg(CH2Ph)2(THF)2 afforded the benzyl i 3 complex Cp*( Pr2MeP)Ru(η -CH2Ph) (2). Complex 2 readily reacted with primary silanes H3SiR F i F (R = trip, dmp, Mes ; trip = 2,4,6- Pr3-C6H2, dmp = 2,6-Mes2-C6H3,Mes = 2,4,6-(CF3)3-C6H2) i to liberate toluene and afford hydrogen-substituted silylene complexes Cp*( Pr2MeP)(H)RudSiH(R) [R = trip, 3;dmp,4;MesF, 5]. Complexes 3-5 exhibit characteristic SiH 1H NMR resonances downfield 2 of 8 ppm and very small JSiH coupling constants (8-10 Hz). The solid state structures of complexes 3 and 5 feature short Ru-Si distances of 2.205(1) and 2.1806(9) A˚, respectively, and planar silicon centers. In i addition, the silylene complex Cp*( Pr2MeP)(H)RudSiPh(trip) (6) and the unusual, chlorine-substituted i species Cp*( Pr2MeP)(H)RudSiCl(R) [R = trip, 7;dmp,8] were prepared. Hydrogen-substituted i ruthenium germylene complex Cp*( Pr2MeP)(H)RudGeH(trip) (9) was prepared similarly by reaction of 2 with tripGeH3. -
Molecular Excitation in the Interstellar Medium: Recent Advances In
Molecular excitation in the Interstellar Medium: recent advances in collisional, radiative and chemical processes Evelyne Roueff∗,† and François Lique∗,‡ Laboratoire Univers et Théories, Observatoire de Paris, 92190, Meudon, France, and LOMC - UMR 6294, CNRS-Université du Havre, 25 rue Philippe Lebon, BP 540, 76058, Le Havre, France E-mail: [email protected]; [email protected] Contents 1 Introduction 3 2 Collisional excitation 7 2.1 Methods . 9 2.1.1 Theory . 9 2.1.2 Potential energy surfaces . 10 2.1.3 Scattering Calculations . 13 arXiv:1310.8259v1 [physics.chem-ph] 30 Oct 2013 2.1.4 Experiments . 17 2.2 H2, CO and H2O molecules as benchmark systems . 19 2.2.1 H2 ....................................... 19 ∗To whom correspondence should be addressed †Laboratoire Univers et Théories, Observatoire de Paris, 92190, Meudon, France ‡LOMC - UMR 6294, CNRS-Université du Havre, 25 rue Philippe Lebon, BP 540, 76058, Le Havre, France 1 2.2.2 CO . 22 2.2.3 H2O...................................... 27 2.3 Other recent results . 30 2.3.1 CN / HCN / HNC . 31 2.3.2 CS / SiO / SiS / SO / SO2 .......................... 34 2.3.3 NH3 /NH................................... 38 2.3.4 O2 / OH / NO . 40 2.3.5 C2 /C2H/C3 /C4 / HC3N.......................... 41 2.3.6 Complex Organic Molecules : H2CO / HCOOCH3 / CH3OH . 45 + + + + + 2.3.7 Cations : CH / SiH / HCO /N2H / HOCO . 49 + 2.3.8 H3 ...................................... 52 − − 2.3.9 Anions : CN /C2H ............................ 52 2.4 Isotopologues . 55 3 Radiative and chemical excitation 57 3.1 Radiative effects . 57 3.2 Chemical effects . 59 3.3 Examples .