The Interactions and Reactions of Atoms and Molecules on the Surfaces of Model Interstellar Dust Grains
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Interstellar Ices and Radiation-Induced Oxidations of Alcohols
The Astrophysical Journal, 857:89 (8pp), 2018 April 20 https://doi.org/10.3847/1538-4357/aab708 © 2018. The American Astronomical Society. All rights reserved. Interstellar Ices and Radiation-induced Oxidations of Alcohols R. L. Hudson and M. H. Moore Astrochemistry Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland, 20771, USA; [email protected] Received 2017 May 2; revised 2018 March 8; accepted 2018 March 9; published 2018 April 18 Abstract Infrared spectra of ices containing alcohols that are known or potential interstellar molecules are examined before and after irradiation with 1 MeV protons at ∼20 K. The low-temperature oxidation (hydrogen loss) of six alcohols is followed, and conclusions are drawn based on the results. The formation of reaction products is discussed in terms of the literature on the radiation chemistry of alcohols and a systematic variation in their structures. The results from these new laboratory measurements are then applied to a recent study of propargyl alcohol. Connections are drawn between known interstellar molecules, and several new reaction products in interstellar ices are predicted. Key words: astrochemistry – infrared: ISM – ISM: molecules – molecular data – molecular processes 1. Introduction 668 cm−1 was produced in solid propargyl alcohol’sIR spectrum after the compound was irradiated with 2 keV Interstellar ices are now recognized as an important comp- electrons (Sivaraman et al. 2015, hereafter SMSB from the onent of the interstellar medium (ISM). The results of multiple coauthors final initials). That IR peak was assigned to benzene infrared (IR) surveys have led to over a dozen assignments of (C H ), which was said “to be the major product from spectral features to molecular ices, with the more abundant 6 6 propargyl alcohol irradiation.” However, a full mid-IR interstellar ices being H O, CO, and CO (Boogert et al. -
UNITED STATES PATENT of FICE 1926,642 PROCESS of OBTAINING REACTION PRODUCTS of RETENE Charles O
Patented Sept. 12, 1933 1926,642 UNITED STATES PATENT of FICE 1926,642 PROCESS OF OBTAINING REACTION PRODUCTS OF RETENE Charles O. Young and George H. Reid, South Charleston, W. Wa, assignors to Carbide & Carbon Chemicals. Corporation, a corporation of New York No Drawing. Application December 2, 1930 Serial No. 502,005 8 Claims. (C. 260-06) The invention is an improved process of mak plied in any desired manner, for example the ap ing reaction products of ketene (CH2=C-O). In paratus for quenching the hot vapors may take general, the process of our invention comprises the form of a packed tower scrubber, spray-scrub thermally decomposing a substance which will ber or any other suitable means for rapidly cool form ketene, and rapidly cooling the hot gaseous ing the hot vapors in intimate contact with the 80 products of this pyrolysis in intimate contact with abSOrbing medium. a reacting absorbing medium. The absorption or quenching means may be The principal object of the invention is to pro operated at ordinary temperatures, and in such Wide a method of making ketene and reaction a case the resultant liquid will contain the reac 0 products thereof which will result in the forma tion product of ketene and the absorbing medium, 65 tion of a maximum amount of valuable product excess absorbing medium and condensed un and which will minimize losses of the ketene changed acetone. The liquid may be circulated formed. until Sufficiently reacted with ketene and then sep In the manufacture of ketene by the pyrolysis arated from the diluent acetone, or it may be oth 15 of organic compounds, e.g., acetone, two primary erwise treated for the separation or recovery of O difficulties in Securing useful quantities of ketene its several constituents. -
Accurate Enthalpies of Formation of Astromolecules: Energy, Stability and Abundance
Accurate Enthalpies of Formation of Astromolecules: Energy, Stability and Abundance Emmanuel E. Etim and Elangannan Arunan* Inorganic and Physical Chemistry Department, Indian Institute of Science Bangalore, India-560012 *email: [email protected] ABSTRACT: Accurate enthalpies of formation are reported for known and potential astromolecules using high level ab initio quantum chemical calculations. A total of 130 molecules comprising of 31 isomeric groups and 24 cyanide/isocyanide pairs with atoms ranging from 3 to 12 have been considered. The results show an interesting, surprisingly not well explored, relationship between energy, stability and abundance (ESA) existing among these molecules. Among the isomeric species, isomers with lower enthalpies of formation are more easily observed in the interstellar medium compared to their counterparts with higher enthalpies of formation. Available data in literature confirm the high abundance of the most stable isomer over other isomers in the different groups considered. Potential for interstellar hydrogen bonding accounts for the few exceptions observed. Thus, in general, it suffices to say that the interstellar abundances of related species are directly proportional to their stabilities. The immediate consequences of this relationship in addressing some of the whys and wherefores among astromolecules and in predicting some possible candidates for future astronomical observations are discussed. Our comprehensive results on 130 molecules indicate that the available experimental enthalpy -
Exhaustive Product Analysis of Three Benzene Discharges by Microwave Spectroscopy Michael C
pubs.acs.org/JPCA Article Exhaustive Product Analysis of Three Benzene Discharges by Microwave Spectroscopy Michael C. McCarthy,* Kin Long Kelvin Lee, P. Brandon Carroll, Jessica P. Porterfield, P. Bryan Changala, James H. Thorpe, and John F. Stanton Cite This: J. Phys. Chem. A 2020, 124, 5170−5181 Read Online ACCESS Metrics & More Article Recommendations *sı Supporting Information ABSTRACT: Using chirped and cavity microwave spectroscopies, automated double resonance, new high-speed fitting and deep learning algorithms, and large databases of computed structures, the discharge products of benzene alone, or in combination with molecular oxygen or nitrogen, have been exhaustively characterized between 6.5 and 26 GHz. In total, more than 3300 spectral features were observed; 89% of these, accounting for 97% of the total intensity, have now been assigned to 152 distinct chemical species and 60 of their variants (i.e., isotopic species and vibrationally excited states). Roughly 50 of the products are entirely new or poorly characterized at high resolution, including many heavier by mass than the precursor benzene. These findings provide direct evidence for a rich architecture of two- and three-dimensional carbon and indicate that benzene growth, particularly the formation of ring−chain molecules, occurs facilely under our experimental conditions. The present analysis also illustrates the utility of microwave spectroscopy as a precision tool for complex mixture analysis, irrespective of whether the rotational spectrum of a product species is known a priori or not. From this large quantity of data, for example, it is possible to determine with confidence the relative abundances of different product masses, but more importantly the relative abundances of different isomers with the same mass. -
One-Step Synthesis of Pyridines and Dihydro- Pyridines in a Continuous Flow Microwave Reactor
One-step synthesis of pyridines and dihydro- pyridines in a continuous flow microwave reactor Mark C. Bagley*1, Vincenzo Fusillo2, Robert L. Jenkins2, M. Caterina Lubinu2 and Christopher Mason3 Full Research Paper Open Access Address: Beilstein J. Org. Chem. 2013, 9, 1957–1968. 1Department of Chemistry, School of Life Sciences, University of doi:10.3762/bjoc.9.232 Sussex, Falmer, Brighton, East Sussex, BN1 9QJ, UK, 2School of Chemistry, Main Building, Cardiff University, Park Place, Cardiff, Received: 05 July 2013 CF10 3AT, UK and 3CEM Microwave Technology Ltd, 2 Middle Slade, Accepted: 11 September 2013 Buckingham, MK18 1WA, UK Published: 30 September 2013 Email: This article is part of the Thematic Series "Chemistry in flow systems III". Mark C. Bagley* - [email protected] Guest Editor: A. Kirschning * Corresponding author © 2013 Bagley et al; licensee Beilstein-Institut. Keywords: License and terms: see end of document. Bohlmann–Rahtz; continuous flow processing; ethynyl ketones; flow chemistry; Hantzsch dihydropyridine synthesis; heterocycles; microwave synthesis; multicomponent reactions; pyridine synthesis Abstract The Bohlmann–Rahtz pyridine synthesis and the Hantzsch dihydropyridine synthesis can be carried out in a microwave flow reactor or using a conductive heating flow platform for the continuous processing of material. In the Bohlmann–Rahtz reaction, the use of a Brønsted acid catalyst allows Michael addition and cyclodehydration to be carried out in a single step without isolation of intermediates to give the corresponding trisubstituted pyridine as a single regioisomer in good yield. Furthermore, 3-substituted propargyl aldehydes undergo Hantzsch dihydropyridine synthesis in preference to Bohlmann–Rahtz reaction in a very high yielding process that is readily transferred to continuous flow processing. -
Nov 15, Ketene Chemistry and the Application in Synthesis by Xuan Zhou
Ketene chemistry and the application in synthesis Dong group at UT Austin Xuan Zhou Nov 14, 2013 Ketene chemistry Content • A brief history of ketene • Type of ketenes • Ketene preparation • Ketenes in synthesis Reviews about ketenes: T. T. Tidwell, Ketenes, 2nd ed., wiley interscience, Hoboken, NJ, 2006. T. T. Tidwell, Eur. J. Org. Chem. 2006, 563-576. T. T. Tidwell, Angew. Chem. Int. Ed. 2005, 44, 5778-5785. A brief history of ketene The first reported ketene: Diphenylketene Wedekind Ketene and its Dimer: N.T.M. Wilsmore, J. Chem. Soc. 1907, 91, 1938 Asymmetric reactions of ketene: H. Pracejus, Justus liebigs Ann. Chem. 1969, 722, 1-11 Bisketenes First prepared bisketenes by Wolf in 1906 O. Diels, B. Wolf, Ber. Dtsch. Chem. Ges. 1906, 39, 689-697 First observed bisketenes in 1982 G. Maier, H. P. Reisenauer, T. Sayrac, Chem. Ber. 1982, 115, 2192 Substituent effects of ketene Melvin Newman Shchukovskaya Cycloadditions of ketenes Lee Irvin Smith Derek H.R. Barton Angew. Chem. Int. Ed. 2005, 44, 5779-5785 Type of ketenes Carbon-substituted ketenes • Alkylketenes 2 3 4 • Alkenylketenes 5 6 7 • alkynylketenes and cyanoketenes 8 9 10 Type of ketenes • Arylketenes 1 2 3 • Acylketenes 4 5 6 • Imidoylketenes 7 azetinones 8 Nitrogen-substituted ketenes 1 Nitroketene Azidoketene Isocyanatoketene 2 Oxygen-substituted ketenes 3 4 5 6 Halogen-substituted ketenes 1 2 3 4 Silyl-ketenes 5 6 7 Phosphorous, sulfur, metal-substituted and bis ketenes 1 2 5 6 7 8 9 10 11 12 Ketene preparation Ketenes from ketene dimers •Pyrolysis of ketene dimer 1 2 3 4 •Photolysis -
The Development of the First Catalyzed Reaction of Ketenes and Imines: Catalytic, Asymmetric Synthesis of Â-Lactams Andrew E
Published on Web 00/00/0000 The Development of the First Catalyzed Reaction of Ketenes and Imines: Catalytic, Asymmetric Synthesis of â-Lactams Andrew E. Taggi, Ahmed M. Hafez, Harald Wack, Brandon Young, Dana Ferraris, and Thomas Lectka* Contribution from the Department of Chemistry, Johns Hopkins UniVersity, 3400 North Charles Street, Baltimore, Maryland 21218 Received February 5, 2002 Abstract: We report practical methodology for the catalytic, asymmetric synthesis of â-lactams resulting from the development of a catalyzed reaction of ketenes (or their derived zwitterionic enolates) and imines. The products of these asymmetric reactions can serve as precursors to a number of enzyme inhibitors and drug candidates as well as valuable synthetic intermediates. We present a detailed study of the mechanism of the â-lactam forming reaction with proton sponge as the stoichiometric base, including kinetics and isotopic labeling studies. Stereochemical models based on molecular mechanics (MM) calculations are also presented to account for the observed stereoregular sense of induction in our reactions and to provide a guidepost for the design of other catalyst systems. Introduction this structural motif a worthwhile goal for the synthetic organic 10 The clinical relevance of â-lactams continues to expand at a chemist, thus the synthesis of these nonantibiotic â-lactams surprising rate. Although their use as antibiotics is being will be the focus of this contribution. While considerable effort compromised to some extent by bacterial resistance pressures,1 has been put into synthetic methodology to construct the basic recently â-lactams (especially nonnatural ones) have achieved â-lactam skeleton, there have been few general methods many important nonantibiotic uses. -
Book of Abstracts
THE PHYSICS AND CHEMISTRY OF THE INTERSTELLAR MEDIUM Celebrating the first 40 years of Alexander Tielens' contribution to Science Book of Abstracts Palais des Papes - Avignon - France 2-6 September 2019 CONFERENCE PROGRAM Monday 2 September 2019 Time Speaker 10:00 Registration 13:00 Registration & Welcome Coffee 13:30 Welcome Speech C. Ceccarelli Opening Talks 13:40 PhD years H. Habing 13:55 Xander Tielens and his contributions to understanding the D. Hollenbach ISM The Dust Life Cycle 14:20 Review: The dust cycle in galaxies: from stardust to planets R. Waters and back 14:55 The properties of silicates in the interstellar medium S. Zeegers 15:10 3D map of the dust distribution towards the Orion-Eridanus S. Kh. Rezaei superbubble with Gaia DR2 15:25 Invited Talk: Understanding interstellar dust from polariza- F. Boulanger tion observations 15:50 Coffee break 16:20 Review: The life cycle of dust in galaxies M. Meixner 16:55 Dust grain size distribution across the disc of spiral galaxies M. Relano 17:10 Investigating interstellar dust in local group galaxies with G. Clayton new UV extinction curves 17:25 Invited Talk: The PROduction of Dust In GalaxIES C. Kemper (PRODIGIES) 17:50 Unravelling dust nucleation in astrophysical media using a L. Decin self-consistent, non steady-state, non-equilibrium polymer nucleation model for AGB stellar winds 19:00 Dining Cocktail Tuesday 3 September 2019 08:15 Registration PDRs 09:00 Review: The atomic to molecular hydrogen transition: a E. Roueff major step in the understanding of PDRs 09:35 Invited Talk: The Orion Bar: from ALMA images to new J. -
Organic Chemical Characterization of Primary and Secondary Biodiesel Exhaust Particulate Matter John Kasumba University of Vermont
University of Vermont ScholarWorks @ UVM Graduate College Dissertations and Theses Dissertations and Theses 2015 Organic Chemical Characterization Of Primary And Secondary Biodiesel Exhaust Particulate Matter John Kasumba University of Vermont Follow this and additional works at: https://scholarworks.uvm.edu/graddis Part of the Environmental Engineering Commons, and the Place and Environment Commons Recommended Citation Kasumba, John, "Organic Chemical Characterization Of Primary And Secondary Biodiesel Exhaust Particulate Matter" (2015). Graduate College Dissertations and Theses. 358. https://scholarworks.uvm.edu/graddis/358 This Dissertation is brought to you for free and open access by the Dissertations and Theses at ScholarWorks @ UVM. It has been accepted for inclusion in Graduate College Dissertations and Theses by an authorized administrator of ScholarWorks @ UVM. For more information, please contact [email protected]. ORGANIC CHEMICAL CHARACTERIZATION OF PRIMARY AND SECONDARY BIODIESEL EXHAUST PARTICULATE MATTER A Dissertation Presented by John Kasumba to The Faculty of the Graduate College of The University of Vermont In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Specializing in Civil and Environmental Engineering May, 2015 Defense Date: October 29, 2014 Dissertation Examination Committee: Britt A. Holmén, Ph.D, Advisor Giuseppe A. Petrucci, Ph.D, Chairperson Donna M. Rizzo, Ph.D Robert G. Jenkins, Ph.D Cynthia J. Forehand, Ph.D., Dean of the Graduate College ABSTRACT Biodiesel use and production has significantly increased in the United States and in other parts of the world in the past decade. This change is driven by energy security and global climate legislation mandating reductions in the use of petroleum-based diesel. -
Ketenes 25/01/2014 Part 1
Baran Group Meeting Hai Dao Ketenes 25/01/2014 Part 1. Introduction Ph Ph n H Pr3N C A brief history Cl C Ph + nPr NHCl Ph O 3 1828: Synthesis of urea = the starting point of modern organic chemistry. O 1901: Wedekind's proposal for the formation of ketene equivalent (confirmed by Staudinger 1911) Wedekind's proposal (1901) 1902: Wolff rearrangement, Wolff, L. Liebigs Ann. Chem. 1902, 325, 129. 2 Wolff adopt a ketene structure in 1912. R 2 hν R R2 1905: First synthesis and characterization of a ketene: in an efford to synthesize radical 2, 1 ROH R C Staudinger has synthesized diphenylketene 3, Staudinger, H. et al., Chem. Ber. 1905, 1735. N2 1 RO CH or Δ C R C R1 1907-8: synthesis and dicussion about structure of the parent ketene, Wilsmore, O O J. Am. Chem. Soc. 1907, 1938; Wilsmore and Stewart Chem. Ber. 1908, 1025; Staudinger and Wolff rearrangement (1902) O Klever Chem. Ber. 1908, 1516. Ph Ph Cl Zn Ph O hot Pt wire Zn Br Cl Cl CH CH2 Ph C C vs. C Br C Ph Ph HO O O O O O O O 1 3 (isolated) 2 Wilsmore's synthesis and proposal (1907-8) Staudinger's synthesis and proposal (1908) wanted to make Staudinger's discovery (1905) Latest books: ketene (Tidwell, 1995), ketene II (Tidwell, 2006), Science of Synthesis, Vol. 23 (2006); Latest review: new direactions in ketene chemistry: the land of opportunity (Tidwell et al., Eur. J. Org. Chem. 2012, 1081). Search for ketenes, Google gave 406,000 (vs. -
Ketene Reactions. I. the Addition of Acid Chlorides
KETENE REACTIONS. I. THE ADDITION OF ACID CHLORIDES TO DIMETHYLKETENE. II. THE CYCLOADDITION OF KETENES TO CARBONYL COMPOUNDS APPROVED: Graduate Committee: Major Professor Committee Member.rr^- Committee Member Committee Member Director of the Department of Chemistry Dean' of the Graduate School Smith, Larry, Ketene Reactions. I. The Addition of Acid Chlorides to DimethyIketene. II. The Cycloaddition of Ketenes to Carbonvl Compounds. Doctor of Philosophy (Chemistry), December, 1970, 63 pp., 3 tables, bibliography, 62 titles. Part I describes the addition of several acid chlorides to dimethylketene. The resulting 3-ketoacid chlorides were isolated and characterized. The reactivities of acid chlorides were found to parallel the parent acid pKa's. A reactivity order of ketenes toward acid chlorides was established. Dimethylketene is more reactive than ketene which is more reactive than diphenylketene. Attempts to effect the addition of an acid halide to a ketene produced by in situ dehydro- halogenation yielded a-halovinyl esters. The addition of acid chlorides to ketenes was concluded to be an ionic process dependent upon the nucleophilic character of the ketene oc- carbon and the polarity of the carbon-chlorine bond in the acid chloride. Part II describes the cycloaddition of several aldo- ketenes to chloral. The ketenes were generated in situ by dehydrohalogenation and dehalogenation of appropriately substituted acyl halides. Both cis- and trans-4-trichloro- Miyl-2-oxetanones are produced in the cycloadditions with the sterically hindered cis isomer predominating. Isomer distributions were determined by vpc or nmr analysis of the reaction solutions. Production of the ketenes by dehalo- genation resulted in enhanced reactivity of the carbonyl compounds. -
Potential for Release of Pulmonary Toxic Ketene from Vaping Pyrolysis of Vitamin E Acetate
Potential for release of pulmonary toxic ketene from vaping pyrolysis of vitamin E acetate Dan Wua,1 and Donal F. O’Sheaa,1 aDepartment of Chemistry, Royal College of Surgeons in Ireland (RCSI), Dublin 2, Ireland Edited by Scott H. Randell, The University of North Carolina at Chapel Hill, and accepted by Editorial Board Member Brigid L. Hogan February 11, 2020 (received for review December 3, 2019) A combined analytical, theoretical, and experimental study has shown and the mode of user usage (9, 10). In reality, a vaping device should that the vaping of vitamin E acetate has the potential to produce be considered as a crude uncontrollable minipyrolysis apparatus ca- exceptionally toxic ketene gas, whichmaybeacontributingfactorto pable of causing changes to the chemical composition of a vaping the upsurge in pulmonary injuries associated with using e-cigarette/ mixture in an unpredictable manner. Specifically, the aryl acetate vaping products. Additionally, the pyrolysis of vitamin E acetate also functional group present within 1 attracted our attention as a func- produces carcinogen alkenes and benzene for which the negative long- tional group sensitive to pyrolysis. The same functional group is term medical effects are well recognized. As temperatures reached in present in phenyl acetate 3, the simplest aryl acetate, which is known vaping devices can be equivalent to a laboratory pyrolysis apparatus, to liberate the highly toxic gas ketene 4 under pyrolysis (Fig. 1). In this the potential for unexpected chemistries to take place on individual article, we describe our initial efforts to illustrate and highlight the components within a vape mixture is high.