DOCSLIB.ORG

IR-UV Spectroscopic Studies of OH and CN Radical Complexes

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
IR-UV Spectroscopic Studies of OH and CN Radical Complexes University of Pennsylvania ScholarlyCommons Publicly Accessible Penn Dissertations 2012 IR-UV Spectroscopic Studies of OH and CN Radical Complexes Bridget Anne O'Donnell University of Pennsylvania, [email protected] Follow this and additional works at: https://repository.upenn.edu/edissertations Part of the Chemistry Commons Recommended Citation O'Donnell, Bridget Anne, "IR-UV Spectroscopic Studies of OH and CN Radical Complexes" (2012). Publicly Accessible Penn Dissertations. 558. https://repository.upenn.edu/edissertations/558 This paper is posted at ScholarlyCommons. https://repository.upenn.edu/edissertations/558 For more information, please contact [email protected]. IR-UV Spectroscopic Studies of OH and CN Radical Complexes Abstract Infrared action spectroscopy is used to identify the OH-HONO2 complex, an intermediate proposed to be important in the reaction of OH with HONO2. Two features are observed in the OH stretching region: a rotationally structured band corresponding to the OH radical stretch and a broadened feature assigned to the OH stretch of HONO2. Assignments are based on vibrational frequencies, analysis of rotational structure, and comparison with ab initio calculations. Nascent OH product state distributions give a binding energy of ≤5.3 kcal mol-1. Infrared action spectroscopy is also used to examine the H2O-HO complex, a primary interaction in the hydration of OH. A rotationally structured band is assigned to the OH radical stretch of H2O-HO. The stability of the complex, ≤5.14 kcal mol-1, is derived from the nascent OH product state distribution. The assignment is supported by ab initio predictions of the spectral shift and dissociation energy. A second feature to lower frequency is attributed to a hot band from an H2O bending state based on theoretical modeling. IR-UV double resonance spectroscopy is used to characterize hindered rotor states in the ground electronic state of CN-Ne and CN-Ar. Infrared spectra exhibit perturbations due to Coriolis coupling: a deperturbation analysis gives rotational constants and coupling strengths. The energetic ordering and spacings of the hindered rotor states provide a probe of the anisotropic intermolecular potential, which is compared with ab initio calculations. The CN monomer is nearly free rotor-like within both complexes. A similar approach yields the infrared spectrum of H2-CN, which exhibits rotational structure consistent with ortho-H2-CN in a linear C≡N-H-H configuration. Lastly, laser-induced fluorescence and IR-UV fluorescence depletion studies are used to characterize the lowest intermolecular levels of CN-Ar correlating with CN B 2Σ+ + Ar. Fluorescence depletion spectra confirm that specificeatur f es originate from a common ground state. The observed energy level pattern and intensity profile eflectr the change in configuration from a weakly anisotropic potential about linear N≡C-Ar in the ground state to linear C≡N-Ar in the excited electronic state. Degree Type Dissertation Degree Name Doctor of Philosophy (PhD) Graduate Group Chemistry First Advisor Marsha I. Lester Keywords cyano radical, hydrogen bond, hydroxyl radical, infrared spectroscopy, rare gas Subject Categories Chemistry This dissertation is available at ScholarlyCommons: https://repository.upenn.edu/edissertations/558 IR-UV SPECTROSCOPIC STUDIES OF OH AND CN RADICAL COMPLEXES Bridget A. O’Donnell A DISSERTATION in Chemistry Presented to the Faculties of the University of Pennsylvania in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy 2012 Supervisor of Dissertation __________________________ Marsha I. Lester Edmund J. Kahn Distinguished Professor Graduate Group Chairperson __________________________ Gary A. Molander, Hirschmann-Makineni Professor of Chemistry Dissertation Committee Michael R. Topp, Professor of Chemistry Jeffery G. Saven, Associate Professor of Chemistry Feng Gai, Professor of Chemistry Dedication To my parents, for their unending support. ii Acknowledgements I owe many thanks to those who have supported and encouraged me throughout my graduate career at Penn. First of all, my advisor Marsha Lester, who has been a wonderful mentor and advisor. I would also like to thank my dissertation committee, Prof. Michael Topp, Prof. Feng Gai, and Prof. Jeffrey Saven, for helpful discussions and guidance. I would also like to thank members of the Lester research group, past and present, who have helped me along the way. Thanks especially to Joseph Beames, who I have worked closely with over the past two years and is more talented than he would care to admit. Thanks also to current graduate students Julia Lehman and Fang Liu. I wish both of you the best of luck at Penn. I would also like to thank past members Eunice Li, Ian Konen, Craig Murray, Logan Dempsey, and Erika Derro, for being patient with me as I began my research and adjusted to the steep learning curve. Last, but certainly not least, I would like to thank my family. To my parents, who have been incredibly supportive of me throughout my academic career and, without whom, I could not have made it to where I am. To my siblings Janey, Ryan, Erin, and Casey, thank you for keeping me sane throughout this process. And finally, to my husband Rob, who has been incredibly patient, I can’t thank you enough for sticking by me through everything. iii Abstract IR-UV SPECTROSCOPIC STUDIES OF OH AND CN RADICAL COMPLEXES Bridget A. O’Donnell Marsha I. Lester Infrared action spectroscopy is used to identify the OH-HONO2 complex, an intermediate proposed to be important in the reaction of OH with HONO2. Two features are observed in the OH stretching region: a rotationally structured band corresponding to the OH radical stretch and a broadened feature assigned to the OH stretch of HONO2. Assignments are based on vibrational frequencies, analysis of rotational structure, and comparison with ab initio calculations. Nascent OH product state distributions give a binding energy of ≤5.3 kcal mol-1. Infrared action spectroscopy is also used to examine the H2O-HO complex, a primary interaction in the hydration of OH. A rotationally structured band is assigned to -1 the OH radical stretch of H2O-HO. The stability of the complex, ≤5.14 kcal mol , is derived from the nascent OH product state distribution. The assignment is supported by ab initio predictions of the spectral shift and dissociation energy. A second feature to lower frequency is attributed to a hot band from an H2O bending state based on theoretical modeling. IR-UV double resonance spectroscopy is used to characterize hindered rotor states in the ground electronic state of CN-Ne and CN-Ar. Infrared spectra exhibit iv perturbations due to Coriolis coupling: a deperturbation analysis gives rotational constants and coupling strengths. The energetic ordering and spacings of the hindered rotor states provide a probe of the anisotropic intermolecular potential, which is compared with ab initio calculations. The CN monomer is nearly free rotor-like within both complexes. A similar approach yields the infrared spectrum of H2-CN, which exhibits rotational structure consistent with ortho-H2-CN in a linear C≡N–H-H configuration. Lastly, laser-induced fluorescence and IR-UV fluorescence depletion studies are used to characterize the lowest intermolecular levels of CN-Ar correlating with CN B 2Σ+ + Ar. Fluorescence depletion spectra confirm that specific features originate from a common ground state. The observed energy level pattern and intensity profile reflect the change in configuration from a weakly anisotropic potential about linear N≡C–Ar in the ground state to linear C≡N–Ar in the excited electronic state. v Table of Contents Abstract............................................................................................................................. iv Table of Contents ............................................................................................................. vi List of Tables .................................................................................................................... xi List of Figures.................................................................................................................xiv Chapter 1 Introduction................................................................................................1 References..................................................................................................19 Chapter 2 Spectroscopic Identification and Stability of the Intermediate in the OH + HONO2 Reaction ...........................................................................24 I. Introduction................................................................................................25 II. Results........................................................................................................29 A. Infrared Action Spectra........................................................................29 B. OH Product State Distribution.............................................................36 C. Insights From Theory...........................................................................40 III. Discussion..................................................................................................44 IV. Materials and Methods...............................................................................46 References..................................................................................................49 Chapter 3 Infrared Spectrum and Stability
Load more

Recommended publications
  • 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.
    [Show full text]
  • 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).
    [Show full text]
  • 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 .
    [Show full text]
  • Arxiv:1510.07052V1 [Astro-Ph.EP] 23 Oct 2015 99 Lae Ta.20,Adrfrne Therein)
    A Chemical Kinetics Network for Lightning and Life in Planetary Atmospheres P. B. Rimmer1 and Ch Helling School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, United Kingdom ABSTRACT There are many open questions about prebiotic chemistry in both planetary and exoplane- tary environments. The increasing number of known exoplanets and other ultra-cool, substellar objects has propelled the desire to detect life and prebiotic 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 K and 30000 K. Formation pathways for glycine and other organic molecules are included. The network is complete up to H6C2N2O3. Stand2015 is successfully tested against atmo- spheric chemistry models for HD209458b, Jupiter and the present-day Earth using a simple 1D photochemistry/diffusion code. Our results for the early Earth agree with those of Kasting (1993) 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. Very little glycine is produced in the absence of any molecular nitrogen and oxygen. This suggests that production of glycine is inhibited if a gas is too strongly reducing. Possible applications and limitations of the chemical kinetics network are also discussed. Subject headings: astrobiology — atmospheric effects — molecular processes — planetary systems 1. Introduction The input energy source and the initial chem- istry have been varied across these different ex- The potential connection between a focused periments.
    [Show full text]
  • Reactivity of N(2D) Atoms and of the Cyano Radical (CN) with Vinyl Cyanide (H2CCHCN) in Titan’S Atmosphere: a Combined Crossed Beam and Theoretical Study
    EPSC Abstracts Vol. 15, EPSC2021-268, 2021 https://doi.org/10.5194/epsc2021-268 Europlanet Science Congress 2021 © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. Reactivity of N(2D) atoms and of the cyano radical (CN) with vinyl cyanide (H2CCHCN) in Titan’s atmosphere: a combined crossed beam and theoretical study Demian Marchione1, Luca Mancini1, Pengxiao Liang1, Gianmarco Vanuzzo1, Piergiorgio Casavecchia1, Dimitrios Skouteris2, Marzio Rosi3, and Nadia Balucani1 1Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy 2Master-Up, Perugia, Italy 3Dipartimento di Ingegneria Civile e Ambientale Università degli Studi di Perugia, Perugia, Italy Several studies have reported model vertical profiles and/or abundance measurements for the main nitrile species observed in Titan’s atmosphere including: hydrogen cyanide (HCN), cyanoacetylene (HC3N), and vinyl cyanide (H2CCHCN) [1-4]. One of the main mechanisms leading to the formation of these nitriles (molecules bearing the CN group) is the reaction of CN radicals with hydrocarbons (molecules with general formula CxHy) involving H elimination (e.g. CN + C2H4=H 2CCHCN + H) or H abstraction (e.g. CN + CH4 = HCN + CH3) [5-9]. In this regard, it is worthwhile to highlight the recent spectroscopic detection of H2CCHCN, obtained using archival data from the Atacama Large Millimeter/submillimeter Array (ALMA), because this species is the best candidate molecule to form stable cell membranes/vesicle structures of
    [Show full text]
  • Arxiv:1606.06230V3 [Physics.Chem-Ph]
    Predissociation of methyl cyanoformate: The HCN and HNC channels Michael J. Wilhelma,∗, Emilio Mart´ınez-Nu´nez˜ b,∗, Jesus´ Gonzalez-V´ azquez´ c, Saulo A. Vazquez´ b, Jonathan M. Smitha, and Hai-Lung Daia aDepartment of Chemistry, Temple University, 1901 N. 13th St., Philadelphia, Pennsylvania 19122, USA. bDepartamento de Qu´ımicaF´ısicaand Centro Singular de Investigaci´onen Qu´ımicaBiol´oxicae Materiais Moleculares (CIQUS), Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain. cDepartamento de Qu´ımica,Universidad Aut´onomade Madrid, M´odulo13, 28049 Madrid, Spain. Abstract We present a combined experimental and theoretical investigation of the 193 nm photolysis of the cyano-ester, methyl cyanoformate (MCF). Specifically, nanosecond time-resolved infrared emission spectroscopy was used to monitor the ro-vibrationally excited photoproducts generated in the photolysis reaction. The signal-to-noise of all time-resolved spectra were enhanced using the recently developed algorithm, spectral reconstruction analysis, which allowed observation of previously obscured minor resonances, and revealed new dissociation channels producing HCN and HNC. Spectral fit analysis of the nascent HCN and electronically 2 excited CN(A Π1) resonances yield a lower bound estimate for the HCN quantum yield of ca. 0.42±0.24%. Multi-configuration self-consistent field calculations were used to interrogate the ground and four lowest energy singlet excited states of MCF. At 193 nm, dissociation is predicted to occur predominantly on the repulsive S2 state. Nevertheless, minor pathways leading to the production of highly excited ground state MCF are available via cascading internal conversion from nascent S2 population. An automated transition-state search algorithm was employed to identify the corresponding ground state dissociation channels, and Rice-Ramsperger-Kassel-Marcus and Kinetic Monte Carlo kinetic simulations were used to calculate the associated branching ratios.
    [Show full text]
  • United States Patent Office Patented June 2, 1964
    3,135,788 United States Patent Office Patented June 2, 1964 1. 2 tine is, if pure, a very stable substance. Further we 3,135,788 PREPARATION OF D-CARNT, NE HYDROCLO. found out that by any conventional method for syn RE FROM TRMETHYLAMNE HYDROCLC). thesizing carnitine, a large amount of by-products are un RDE AND EPHALOGENGHYORN avoidably formed, and that the instability of carnitine funzo Noguchi, Kanazawa, and Naoichi Sakota, Nishi would be ascribable to the presence of such by-products nomiya, Japan, assignors to Nihon Zoki Seiyaku Kabu which are practically impossible to remove from carnitine shikikaisha, Osaka, Japan, a corporation of Japan even by recrystallization. As a logical consequence, it No Drawing. Filed July 18, 1960, Ser. No. 43,275 ensues that a synthetic method for preparing carnitine Ciainas priority, application Japan Sept. 28, 1959 must satisfy the following three conditions; namely, i0 Claims. (C. 269-53) O (1) Carnitine should be produced in a high yield, This invention relates to a method for the preparation (2) The amount of by-products accompanying through of DL-carnitine hydrochloride, and in particular, to a all the steps should be minimum, novel synthetic method for preparing DL-carnitine hy (3) Said by-products should be readily removable from drochloride of high purity in a good yield. the final product, carnitine. The chemical nomenclature of said DL-carnitine hy 15 We have accomplished, as a result of numerous experi drochloride is DL-y-trimethyl ammonium-6-hydroxy ments, the method of this invention which satisfies the butyrate hydrochloride represented by the following con above three requirements.
    [Show full text]
  • Theoretical Studies of Ground and Excited State Reactivity
    Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1179 Theoretical Studies of Ground and Excited State Reactivity POORIA FARAHANI ACTA UNIVERSITATIS UPSALIENSIS ISSN 1651-6214 UPPSALA urn:nbn:se:uu:diva-232219 2014 Dissertation presented at Uppsala University to be publicly examined in Häggsalen, Ångström laboratory, Uppsala, Thursday, 30 October 2014 at 13:00 for the degree of Doctor of Philosophy. The examination will be conducted in English. Faculty examiner: Prof Isabelle Navizet (Université PARIS-EST). Abstract Farahani, P. 2014. Theoretical Studies of Ground and Excited State Reactivity. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1179. 86 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-554-9036-2. To exemplify how theoretical chemistry can be applied to understand ground and excited state reactivity, four different chemical reactions have been modeled. The ground state chemical reactions are the simplest models in chemistry. To begin, a route to break down halomethanes through reactions with ground state cyano radical has been selected. Efficient explorations of the potential energy surfaces for these reactions have been carried out using the artificial force induced reaction algorithm. The large number of feasible pathways for reactions of this type, up to eleven, shows that these seemingly simple reactions can be quite complex. This exploration is followed by accurate quantum dynamics with reduced dimensionality for the reaction between − Cl and PH2Cl. The dynamics indicate that increasing the dimensionality of the model to at least two dimensions is a crucial step for an accurate calculation of the rate constant.
    [Show full text]
  • Formation of Polycyclic Aromatic Hydrocarbons and Nitrogen
    Florida International University FIU Digital Commons FIU Electronic Theses and Dissertations University Graduate School 10-24-2013 Formation of Polycyclic Aromatic Hydrocarbons and Nitrogen Containing Polcyclic Aromatic Compounds in Titan's Atmosphere, the Interstellar Medium and Combustion Alexander Landera Florida International University, [email protected] DOI: 10.25148/etd.FI13120424 Follow this and additional works at: https://digitalcommons.fiu.edu/etd Part of the Physical Chemistry Commons Recommended Citation Landera, Alexander, "Formation of Polycyclic Aromatic Hydrocarbons and Nitrogen Containing Polcyclic Aromatic Compounds in Titan's Atmosphere, the Interstellar Medium and Combustion" (2013). FIU Electronic Theses and Dissertations. 991. https://digitalcommons.fiu.edu/etd/991 This work is brought to you for free and open access by the University Graduate School at FIU Digital Commons. It has been accepted for inclusion in FIU Electronic Theses and Dissertations by an authorized administrator of FIU Digital Commons. For more information, please contact [email protected]. FLORIDA INTERNATIONAL UNIVERSITY Miami, Florida FORMATION OF POLYCYCLIC AROMATIC HYDROCARBONS AND NITROGEN CONTAINING POLYCYCLIC AROMATIC COMPOUNDS IN TITAN’S ATMOSPHERE, THE INTERSTELLAR MEDIUM AND COMBUSTION A dissertation submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSPHY in CHEMISTRY by Alexander Landera 2013 To: Dean Kenneth G. Furton College of Arts and Sciences This dissertation, written by Alexander Landera, and entitled Formation of Polycyclic Aromatic Hydrocarbons and Nitrogen Containing Polycyclic Aromatic Compounds in Titan's atmosphere, the Interstellar Medium and Combustion, having been approved in respect to style and intellectual content, is referred to you for judgment. We have read this dissertation and recommend that it be approved.
    [Show full text]
  • The Reductive Decyanation Reaction: an Overview and Recent Developments Jean-Marc Mattalia
    The reductive decyanation reaction: an overview and recent developments Jean-Marc Mattalia To cite this version: Jean-Marc Mattalia. The reductive decyanation reaction: an overview and recent developments. Beilstein Journal of Organic Chemistry, Beilstein-Institut, 2017, 13, pp.267-284. 10.3762/bjoc.13.30. hal-01480621 HAL Id: hal-01480621 https://hal.archives-ouvertes.fr/hal-01480621 Submitted on 14 May 2018 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. The reductive decyanation reaction: an overview and recent developments Jean-Marc R. Mattalia Review Open Access Address: Beilstein J. Org. Chem. 2017, 13, 267–284. Aix-Marseille Univ, CNRS, Centrale Marseille, iSm2, Marseille, France doi:10.3762/bjoc.13.30 Email: Received: 20 October 2016 Jean-Marc R. Mattalia - [email protected] Accepted: 25 January 2017 Published: 13 February 2017 Keywords: Associate Editor: J. A. Murphy α-aminonitrile; decyanation; electron donor; hydride; malononitrile; transition metal catalysis © 2017 Mattalia; licensee Beilstein-Institut. License and terms: see end of document. Abstract This review presents an overview of the reductive decyanation reaction with a special interest for recent developments. This trans- formation allows synthetic chemists to take advantages of the nitrile functional group before its removal.
    [Show full text]
  • Nickel-Catalyzed Reductive Arylation of Redox Active Esters for the Synthesis of -Aryl Nitriles – Role of a Chlorosilane Additive Nicholas W
    Nickel-Catalyzed Reductive Arylation of Redox Active Esters for the Synthesis of -Aryl Nitriles – Role of a Chlorosilane Additive Nicholas W. M. Michel§, Racquel K. Edjoc§, Emmanuel Fagbola§, Jonathan M. E. Hughes‡, Louis- Charles Campeau‡, Sophie A. L. Rousseaux§* AUTHOR ADDRESS § Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, CANADA ‡ Department of Process Research and Development, Merck & Co. Inc., Rahway, New Jersey 07065, United States KEYWORDS nickel catalysis, reductive cross-coupling, chlorosilane, α-aryl nitrile, arylation, radical, NHP ester ABSTRACT: A nickel-catalyzed reductive cross-coupling of redox-active N-hydroxyphthalimide (NHP) esters and iodoarenes for the synthesis of α-aryl nitriles is described. The NHP ester substrate is derived from cyanoacetic acid, which allows for a modular synthesis of substituted -aryl nitriles, an important scaffold in pharmaceutical sciences. Mechanistic studies reveal that decarboxylation of the NHP ester to the reactive radical intermediate is accomplished by a combination of a chlorosilane additive and Zn dust. The reaction exhibits a broad scope as many functional groups are compatible under the reaction conditions, including complex highly functionalized medicinal agents. Scheme 1. α-Aryl nitrile synthesis via cross-coupling intermediates and their prevalence in pharmaceutical agents. Thus, considerable efforts have been dedicated to their synthesis.2 Traditionally, feedstock chemicals such as aliphatic nitriles3 or cyanoacetate salts4 can undergo α-arylation as a nucleophilic reagent in the presence of an aryl(pseudo)halide coupling partner with a transition-metal catalyst such as Pd (Scheme 1a, left). However, these established α-arylation methods require strongly basic reaction conditions and/or high temperatures to generate the nucleophilic coupling partner, which limits both their functional group compatibility and their use in late-stage diversification of complex molecules.
    [Show full text]
  • Quantum Chemical Analysis of Stable Noble Gas Cations for Astrochemical Detection Carlie M
    Georgia Southern University Digital Commons@Georgia Southern University Honors Program Theses 2018 Quantum Chemical Analysis of Stable Noble Gas Cations for Astrochemical Detection Carlie M. Novak Georgia Southern University Follow this and additional works at: https://digitalcommons.georgiasouthern.edu/honors-theses Part of the Physical Chemistry Commons, and the Theory and Algorithms Commons Recommended Citation Novak, Carlie M., "Quantum Chemical Analysis of Stable Noble Gas Cations for Astrochemical Detection" (2018). University Honors Program Theses. 311. https://digitalcommons.georgiasouthern.edu/honors-theses/311 This thesis (open access) is brought to you for free and open access by Digital Commons@Georgia Southern. It has been accepted for inclusion in University Honors Program Theses by an authorized administrator of Digital Commons@Georgia Southern. For more information, please contact [email protected]. Quantum Chemical Analysis of Stable Noble Gas Cations for Astrochemical Detection An Honors Thesis submitted in partial fulfillment of the requirements for Honors in the Department of Chemistry and Biochemistry By Carlie M. Novak Under the mentorship of Dr. Ryan C. Fortenberry ABSTRACT The search for possible, natural, noble gas molecules has led to quantum chemical, spec- troscopic analysis of NeCCH+, ArNH+, ArCCH+, and ArCN+. Each of these systems have been previously shown to be a stable minimum on its respective potential energy surface. However, no spectroscopic data are available for laboratory detection or interstellar obser- vation of these species, and the interstellar medium may be the most likely place, in nature, where these noble gas cations are found. The bent shape of NeCCH+ is confirmed here with a fairly large dipole moment and a bright C { H stretching frequency at 3101.9 cm−1.
    [Show full text]