DOCSLIB.ORG

Benchmark DFT Approach for Dissociation Energies of Chemically Important Bonds

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Benchmark DFT Approach for Dissociation Energies of Chemically Important Bonds Benchmark DFT Approach for Dissociation Energies of Chemically Important Bonds By Naveen Kosar CIIT/FA15-R66-002/ATD PhD Thesis In Chemistry COMSATS University Islamabad Abbottabad Campus - Pakistan Spring, 2019 i COMSATS University Islamabad Benchmark DFT Approach for Dissociation Energies of Chemically Important Bonds A Thesis Presented to COMSATS University Islamabad, Abbottabad Campus In partial fulfillment of the requirement for the degree of PhD (Chemistry) By Naveen Kosar CIIT/FA15-R66-002/ATD Spring, 2019 ii Benchmark DFT Approach for Dissociation Energies of Chemically Important Bonds A Post Graduate Thesis submitted to the Department of Chemistry as partial fulfillment of the requirement for the award of Degree of Ph.D in Chemistry. Name Registration Number Naveen Kosar CIIT/FA15-R66-002/ATD Supervisor Dr. Tariq Mahmood Associate Professor Department of Chemistry COMSATS University Islamabad, Abbottabad Campus Co-Supervisor Dr. Khurshid Ayub Associate Professor Department of Chemistry COMSATS University Islamabad, Abbottabad Campus iii iv v vi vii DEDICATION I would like to dedicate my thesis to my beloved Parents, supportive Family and encouraging Teachers viii ACKNOWLEDGEMENTS “All the praises and thanks be to Allah, Who has guided us to this, and never could we have found guidance, were it not that Allah had guided us!” (Aayah No. 43, Surah Al-A’raf, Chapter No. 7, Holy Qur’an). My thousands Drood and Slam for Holy Prophet Mohammad (SAW) who emphasized the Umma to seek knowledge from the cradle to grave. First, I am thankful to my supervisor Dr. Tariq Mahmood and co-supervisor Dr. Khurshid Ayub, for their excellent supervision and guidance throughout my PhD research. They always pushed me forward and encouraged to have firm belief in myself. I extend my gratitude to Dr. Umar Rashid, Department of Chemistry, for his motivation and moral support throughout my research work. I am very thankful to Dr. Syeda Samina Ejaz, Department of Biochemistry, Islamia University Bahawalpur, for her valuable guidance and suggestion regarding my research work. I am very thankful to Dr. Mazhar A. Gilani, Department of Chemistry, COMSATS University Islamabad, Lahore Campus, for his valuable critics regarding the writing of publications were worthwhile. I acknowledge the Higher Education Commision, Pakistan and COMSATS University Islamabad, Abbottabad Campus for providing funding against my research project which really helped to carry out this research work. Second, my deepest gratitude goes to my entire family for their continuous encouragement, constant support, and unconditional love that gave me strength during PhD. Special thanks to my cousin, Farukh Shahzad Khan, for his help, guidance and suggestion to achieve this success. Bundle of thanks to my parents, Zahir Ahmad Khan and Razia Sultana, who raised me with a love of science and supported me in all my pursuits. Thanks, are extended to my grandmothers and aunts, for their prayers and wishes. I would also like to thank to my dear sister (Ayesha Zaheer) and brothers (Saud Ahmad Khan and Masroor Ahmed Khan) for encouragement and support. I would like to pay my gratitude to my Uncles (Sajjad Ahmad Khan, Sabir Ahmad Khan, Shakir Ahmad Khan, Abdur Rashid Ahmad Khan, Riaz Ali Khan, Hadayth Ullah Khan, Azhar Iqbal Khan, Anwar Iqbal Khan and Ishtiaq Khan) and their families for their support, wishes and prayers. Finally, I am very thankful to all my friends (Abida, Sidra, Saira, Humira, Amna, Aqsa, Romana and Muneeba) for their encouragement and support throughout this journey. Next, Lab colleagues (Riffat, Maria, Saira, Saima, Sehrish, Tanzeela, Rabia, Zainab, Fatima, Maria, Sajida, Saba, Saima, Ridda, Iram, Arenda, Muneeba, Hira, Sana, Kiran, Annum, Maryam, Nadia, Sidra, Mamoona, Saba, Yasir, Tabish, Hasnain, Faizan, Asghar, Akhtar, Sajjad, Arsalan, Zulqarnain, Asad and Bilal) at the department, COMSATS University Islamabad, Abbottabad Campus, for their valuable feedback, discussion, comments and support throughout my PhD research. Naveen Kosar CIIT/FA15-R66-002/ATD ix ABSTRACT Benchmark DFT Approach for Dissociation Energies of Chemically Important Bonds A very fascinating aspect in quantum chemical research is to acquire accurate and cost- effective method for the calculation of electronic as well as structural properties. The benchmarking is a famous approach where theoretical results from low-level calculations are compared with accurate high-level quantum chemical methods or experimental results. The current study focuses on performance evaluation of density functional theory methods for accurate measurement of bond dissociation energies. Bond dissociation energy (BDE) measurement has got noteworthy attention due to its importance in all areas of chemistry. Keeping in view the importance of bond dissociation energy (BDE), the current study is focused on the exploration of accurate and low cost DFT method for bond dissociation energy calculations of different chemically important bonds. The selected bonds include C−X (X = Cl and Br), C−Sn, C−CN, C−Mg and M−O2 bonds. Various functionals of DFT classes with a variety of basis sets are implemented for the calculation of BDE. The accuracy of a method is examined through different statistical tests including root mean square deviation (RMSD), standard deviation (SD), Pearson’s correlation (R) and mean absolute error (MAE). Theoretical results are compared with the already reported experimental BDE values of respective bonds. The method which has less deviation and error with a reasonable Pearson’s correlation is considered as the method of interest. For the BDE measurement of carbon halogen (C−X where X = Cl and Br) bond, 33 different density functionals (DFs) with four basis sets are used for sixteen halogen containing compounds. Two basis sets (6-31G(d) and 6-311G(d)) are selected from Pople basis sets and other two are selected from Dunning basis sets (aug-cc-pVDZ and aug-cc-pVTZ). Among all selected DFs, ꞷB97X-D shows the best performance with least deviations (RMSD, SD), error (MAE) and a significant Pearson's correlation (R) when compared with experimental data. Secondly, nineteen DFs from eight different DFT classes with four basis sets are selected for BDE calculation of the C−Sn bond of ten organotin compounds. Two basis sets containing pseudopotential basis sets (LANL2DZ and SDD) and other are selected from Karlsruhe basis sets (def2-SVP and x def2-TZVP). In this benchmark approach, BLYP-D3 functional of dispersion corrected GGA class with SDD basis set is observed as the best method for homolytic BDE calculation of C−Sn bond. Thirdly, for twelve organo-nitrile compounds thirty-one DFs with eight basis sets including Pople, Dunning and Karlsruhe basis sets are used. Thus, 6-31G(d), 6-31G(d,p), 6-311G(d,p), 6-31+G(d) and 6-311++G(d,p) basis sets are selected from Pople basis sets, aug-cc-pVDZ and aug-cc-pVTZ basis sets are selected from Dunning basis sets and def2-SVP basis set is selected from Karlsruhe basis sets. Overall, CAM-B3LYP functional of range separated hybrid GGA class with Pople’s 6- 311G(d,p) basis set provides the most accurate results for the BDE measurement of C−CN bond of nitrile compounds. Fourthly, twenty-nine DFs from thirteen DFT classes with four basis sets (Pople’s 6-31G(d) and 6-311G(d), Dunning’s aug-ccpVDZ and Karlsruhe’s def2-SVP basis sets) are implemented for BDE measurement of C−Mg bond of fifteen Grignard reagents. TPSS of meta-GGA class with 6-31G(d) basis set gave the accurate results. Finally, for BDE measurements of M−O2 bond in five metal complexes with dioxygen, fourteen DFs are chosen from seven DFT classes with two series of mixed basis sets. A combination of pseudopotential and Pople basis sets (LANL2DZ & 6-31G(d) and SDD & 6-31+G(d)) are used as a series of mixed basis sets. M06 functional with SDD & 6-31+G(d) gave outstanding results due to low deviations, error and the best R between experimental and theoretical data. xi PUBLICATIONS ASSOCIATED WITH THESIS 1. Naveen Kosar, Tariq Mahmood, Khurshid Ayub. (2017). Role of dispersion corrected hybrid GGA class in accurately calculating the bond dissociation energy of carbon halogen bond: A benchmark study. Journal of Molecular Structure, 1150, 447-458. (IF = 2.120) 2. Naveen Kosar, Khurshid Ayub, Tariq Mahmood. (2018). Accurate theoretical method for homolytic cleavage of C−Sn bond: A benchmark approach. Computational and Theoretical Chemistry, 1140, 134-144. (IF = 1.344) 3. Naveen Kosar, Khurshid Ayub, Mazhar Amjad Gilani, Tariq Mahmood. (2019). Benchmark DFT studies on C−CN homolytic cleavage and screening the substitution effect on bond dissociation energy. Journal of Molecular Modeling, 25, 47-60. (IF = 1.335) 4. Naveen Kosar, Khurshid Ayub, Mazhar A Gailani, Faheem Shah, Tariq Mahmood. Benchmark approach in search of cost-effective and accurate density functional for homolytic cleavage of C-Mg bond of Grignard reagent. International Journal of Quantum Chemistry, 2019, e26106 (IF = 2.263) xii TABLE OF CONTENTS 1 Introduction ................................................................................................ 1 1.1 Theoretical Chemistry ............................................................................ 2 1.1.1 Applications of Computational Chemistry ..................................... 3 1.1.2 Limitations ...................................................................................... 3 1.2 Computational versus Experimental Chemistry .................................... 4 1.3 Benchmark Study ..................................................................................
Load more

Recommended publications
  • Hydroxyacetonitrile (HOCH2CN) As a Precursor for Formylcyanide (CHOCN), Ketenimine (CH2CNH), and Cyanogen (NCCN) in Astrophysical Conditions
    A&A 549, A93 (2013) Astronomy DOI: 10.1051/0004-6361/201219779 & c ESO 2013 Astrophysics Hydroxyacetonitrile (HOCH2CN) as a precursor for formylcyanide (CHOCN), ketenimine (CH2CNH), and cyanogen (NCCN) in astrophysical conditions G. Danger1, F. Duvernay1, P. Theulé1, F. Borget1, J.-C. Guillemin2, and T. Chiavassa1 1 Aix-Marseille Univ, CNRS, PIIM UMR 7345, 13397 Marseille, France e-mail: [email protected] 2 Institut des Sciences Chimiques de Rennes, École Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, Avenue du Général Leclerc, CS 50837, 35708 Rennes Cedex 7, France Received 8 June 2012 / Accepted 19 November 2012 ABSTRACT Context. The reactivity in astrophysical environments can be investigated in the laboratory through experimental simulations, which provide understanding of the formation of specific molecules detected in the solid phase or in the gas phase of these environments. In this context, the most complex molecules are generally suggested to form at the surface of interstellar grains and to be released into the gas phase through thermal or non-thermal desorption, where they can be detected through rotational spectroscopy. Here, we focus our experiments on the photochemistry of hydroxyacetonitrile (HOCH2CN), whose formation has been shown to compete with aminomethanol (NH2CH2OH), a glycine precursor, through the Strecker synthesis. Aims. We present the first experimental investigation of the ultraviolet (UV) photochemistry of hydroxyacetonitrile (HOCH2CN) as a pure solid or diluted in water ice. Methods. We used Fourier transform infrared (FT-IR) spectroscopy to characterize photoproducts of hydroxyacetonitrile (HOCH2CN) and to determine the different photodegradation pathways of this compound. To improve the photoproduct identifications, irradiations of hydroxyacetonitrile 14N and 15N isotopologues were performed, coupled with theoretical calculations.
    [Show full text]
  • Gouvernement Du Canada
    50-1443-eng-cov.qxd 5/18/00 19:56 Page 1 Environment Environnement Canada Canada Health Santé Canada Canada Canadian Environmental Protection Act, 1999 PRIORITY SUBSTANCES LIST ASSESSMENT REPORT Acrylonitrile Canada 50-1443-eng-cov.qxd 5/18/00 19:56 Page 2 Canadian Cataloguing in Publication Data Priority substances list assessment report: acrylonitrile (Priority substances list assessment report) Issued also in French under title: Liste des substances d'intérêt prioritaire, rapport d'évalua- tion, acrylonitrile. Canadian Environmental Protection Act. Includes bibliographical references. Co-published by Health Canada. Issued also on the Internet. ISBN 0-662-28587-5 Cat. no. En40-215/49E 1. Acrylonitrile -- Toxicity testing -- Canada. 2. Acrylonitrile -- Environmental aspects -- Canada. 3. Environmental monitoring -- Canada. I. Canada. Environment Canada. II. Canada. Health Canada. III. Series. TD887.A37P74 2000 363.738'4 C00-980073-5 Additional information can be obtained at Environment Canadas Web site at www.ec.gc.ca or from the Inquiry Centre at 1-800-668-6767. © Minister of Public Works and Government Services 2000 50-1443-eng-cov.qxd 5/18/00 19:56 Page 3 Canadian Environmental Protection Act, 1999 PRIORITY SUBSTANCES LIST ASSESSMENT REPORT Acrylonitrile Environment Canada Health Canada May 2000 50-1443-eng.qxd 5/29/00 14:48 Page 1 TABLE OF CONTENTS SYNOPSIS .................................................................................................................... 1 1.0 INTRODUCTION ...............................................................................................
    [Show full text]
  • 39. Acrylonitrile アクリロニトリル
    IPCS UNEP//ILO//WHO 国際化学物質簡潔評価文書 Concise International Chemical Assessment Document No.39 Acrylonitrile(2002) アクリロニトリル 世界保健機関 国際化学物質安全性計画 国立医薬品食品衛生研究所 安全情報部 2007 目 次 序 言 1． 要 約 ------------------------------------------------------------------------------------------- 5 2． 物質の特定および物理的・化学的性質 ----------------------------------------------- 7 3． 分析方法 -------------------------------------------------------------------------------------- 8 4． ヒトおよび環境の暴露源 ----------------------------------------------------------------- 10 4.1 自然界での発生源 ------------------------------------------------------------------------- 10 4.2 人為的発生源 ------------------------------------------------------------------------------- 10 4.3 生産と用途 ---------------------------------------------------------------------------------- 10 5． 環境中の移動・分布・変換 -------------------------------------------------------------- 11 5.1 大 気 ------------------------------------------------------------------------------------------ 11 5.2 水 ---------------------------------------------------------------------------------------------- 11 5.3 土壌と底質 ---------------------------------------------------------------------------------- 12 5.4 生物相 ---------------------------------------------------------------------------------------- 12 5.5 環境中分配 ---------------------------------------------------------------------------------- 13 6． 環境中の濃度とヒトの暴露量 ------------------------------------------------------------ 14 6.1 環境中の濃度 ------------------------------------------------------------------------------- 14 6.1.1
    [Show full text]
  • Hydroxyacetonitrile (HOCH2CN)
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by HAL-Rennes 1 Hydroxyacetonitrile (HOCH2CN) as a precursor for formylcyanide (CHOCN), ketenimine (CH2CNH), and cyanogen (NCCN) in astrophysical conditions G Danger, F Duvernay, P Theul´e,Fabien Borget, J.-C Guillemin, T Chiavassa To cite this version: G Danger, F Duvernay, P Theul´e, Fabien Borget, J.-C Guillemin, et al.. Hy- droxyacetonitrile (HOCH2CN) as a precursor for formylcyanide (CHOCN), keten- imine (CH2CNH), and cyanogen (NCCN) in astrophysical conditions. Astronomy and Astrophysics - A&A, EDP Sciences, 2013, Astronomy and Astrophysics, 549, pp.A93. <http://www.aanda.org/articles/aa/abs/2013/01/aa19779-12/aa19779-12.html>. <10.1051/0004-6361/201219779>. <hal-01244747> HAL Id: hal-01244747 https://hal-amu.archives-ouvertes.fr/hal-01244747 Submitted on 16 Dec 2015 HAL is a multi-disciplinary open access L'archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destin´eeau d´ep^otet `ala diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publi´esou non, lished or not. The documents may come from ´emanant des ´etablissements d'enseignement et de teaching and research institutions in France or recherche fran¸caisou ´etrangers,des laboratoires abroad, or from public or private research centers. publics ou priv´es. A&A 549, A93 (2013) Astronomy DOI: 10.1051/0004-6361/201219779 & c ESO 2013 Astrophysics Hydroxyacetonitrile (HOCH2CN) as a precursor for formylcyanide (CHOCN), ketenimine (CH2CNH), and cyanogen (NCCN) in astrophysical conditions G. Danger1, F. Duvernay1, P. Theulé1, F.
    [Show full text]
  • Assessment Report on Acrylonitrile for Developing an Ambient Air Quality Guideline
    ASSESSMENT REPORT ON AACCRRYYLLOONNIITTRRIILLEE FOR DEVELOPING AN AMBIENT AIR QUALITY GUIDELINE ASSESSMENT REPORT ON ACRYLONITRILE FOR DEVELOPING AN AMBIENT AIR QUALITY GUIDELINE Prepared for Alberta Environment By WBK & Associates Inc. March 2002 Pub. No: T/663 ISBN: 0-7785-2258-X (Printed Edition) ISBN: 0-7785-2260-1 (On-line Edition) Web Site: http://www3.gov.ab.ca/env/info/infocentre/publist.cfm Although prepared with funding from Alberta Environment (AENV), the contents of this report/document do not necessarily reflect the views or policies of AENV, nor does mention of trade names or commercial products constitute endorsement or recommendation for use. Any comments, questions, or suggestions regarding the content of this document may be directed to: Science and Standards Branch Alberta Environment 4th Floor, Oxbridge Place 9820 – 106th Street Edmonton, Alberta T5K 2J6 Fax: (780) 422-4192 Additional copies of this document may be obtained by contacting: Information Centre Alberta Environment Main Floor, Great West Life Building 9920 – 108th Street Edmonton, Alberta T5K 2M4 Phone: (780) 944-0313 Fax: (780) 427-4407 Email: [email protected] FOREWORD Alberta Environment maintains Ambient Air Quality Guidelines to support air quality management in Alberta. Alberta Environment currently has ambient guidelines for thirty-one substances and five related parameters. These guidelines are periodically updated and new guidelines are developed as required. Fact Sheets on Ambient Air Quality Guidelines were updated in September 1997 and February 2000. With the assistance of the Clean Air Strategic Alliance, a multi-stakeholder workshop was held in October 2000 to set Alberta’s priorities for the next three years.
    [Show full text]
  • European Union Risk Assessment Report
    CN N EINECS No: 203-466-5 857 E lonitrile CH y EUR 20 acr C 2 H CAS No: 107-13-1 European Union Risk Assessment Report Protection 32 : Substances Priority List st European Institute for Health and Consumer 1 Bureau Chemicals Existing Volume European Chemicals Bureau European Union Risk Assessment Report CAS: 107-13-1 EC: 203-466-5 acrylonitrile 32 PL-1 European Union Risk Assessment Report ACRYLONITRILE CAS No: 107-13-1 EINECS No: 203-466-5 RISK ASSESSMENT LEGAL NOTICE Neither the European Commission nor any person acting on behalf of the Commission is responsible for the use which might be made of the following information A great deal of additional information on the European Union is available on the Internet. It can be accessed through the Europa Server (http://europa.eu.int). © European Communities, 2004 Reproduction is authorised provided the source is acknowledged. ACRYLONITRILE CAS No: 107-13-1 EINECS No: 203-466-5 RISK ASSESSMENT Final Report, 2004 The risk assessment of acrylonitrile has been prepared by Ireland on behalf of the European Union. The scientific work contained in the report has been prepared by the Hazardous Substances Assessment Unit of the Health and Safety Authority. Contact: Hazardous Substances Assessment Unit Health and Safety Authority, 10, Hogan Place, Dublin 2 Mrs Roisin McEneany, Dr Majella Cummins Tel: 353-1-6147000 Fax: 353-1-6147017 E-mail: [email protected] Date of Last Literature Search: 1999 Review of report by MS Technical Experts finalised: 2000 Final report: 2004 Foreword We are pleased to present this Risk Assessment Report which is the result of in-depth work carried out by experts in one Member State, working in co-operation with their counterparts in the other Member States, the Commission Services, Industry and public interest groups.
    [Show full text]
  • TOXICOLOGICAL PROFILE for ACRYLONITRILE Agency for Toxic Substances and Disease Registry U.S. Public Health Service Decembe
    TOXICOLOGICAL PROFILE FOR ACRYLONITRILE Agency for Toxic Substances and Disease Registry U.S. Public Health Service December 1990 ii DISCLAIMER The use of company or product name(s) is for identification only and does not imply endorsement by the Agency for Toxic Substances and Disease Registry. 1 1. PUBLIC HEALTH STATEMENT This Statement was prepared to give you information about acrylonitrile and to emphasize the human health effects that may result from exposure to it. The Environmental Protection Agency (EPA) has identified 1,177 sites on its National Priorities List (NPL). Acrylonitrile has been found at 3 of these sites. However, we do not know how many of the 1,177 NPL sites have been evaluated for acrylonitrile. As EPA evaluates more sites, the number of sites at which acrylonitrile is found may change. The information is important for you to know because acrylonitrile may cause harmful health effects and because these sites are potential or actual sources of human exposure to acrylonitrile. When a chemical is released from a large area, such as an industrial plant, or from a container, such as a drum or bottle, it enters the environment as a chemical emission. This emission, which is also called a release, does not always lead to exposure. You can be exposed to a chemical only when you come into contact with the chemical. You may be exposed to it in the environment by breathing, eating, or drinking substances containing the chemical or from skin contact with it. If you are exposed to a hazardous substance such as acrylonitrile, several factors will determine whether harmful health effects will occur and what the type and severity of those health effects will be.
    [Show full text]
  • CICAD on Acrylonitrile Was Prepared Jointly Being Limited; Reaction and Advection Are the Major by the Environmental Health Directorate of Health Removal Mechanisms
    This report contains the collective views of an international group of experts and does not necessarily represent the decisions or the stated policy of the United Nations Environment Programme, the International Labour Organization, or the World Health Organization. Concise International Chemical Assessment Document 39 ACRYLONITRILE Please note that the layout and pagination of this pdf file are not necessarily identital to those of the printed copy First draft prepared by G. Long and M.E. Meek, Health Canada, Ottawa, Canada, and P. Cureton, Environment Canada, Ottawa, Canada Published under the joint sponsorship of the United Nations Environment Programme, the International Labour Organization, and the World Health Organization, and produced within the framework of the Inter-Organization Programme for the Sound Management of Chemicals. World Health Organization Geneva, 2002 The International Programme on Chemical Safety (IPCS), established in 1980, is a joint venture of the United Nations Environment Programme (UNEP), the International Labour Organization (ILO), and the World Health Organization (WHO). The overall objectives of the IPCS are to establish the scientific basis for assessment of the risk to human health and the environment from exposure to chemicals, through international peer review processes, as a prerequisite for the promotion of chemical safety, and to provide technical assistance in strengthening national capacities for the sound management of chemicals. The Inter-Organization Programme for the Sound Management of Chemicals (IOMC) was established in 1995 by UNEP, ILO, the Food and Agriculture Organization of the United Nations, WHO, the United Nations Industrial Development Organization, the United Nations Institute for Training and Research, and the Organisation for Economic Co-operation and Development (Participating Organiza- tions), following recommendations made by the 1992 UN Conference on Environment and Development to strengthen cooperation and increase coordination in the field of chemical safety.
    [Show full text]
  • Arxiv:1809.09132V1 [Astro-Ph.GA] 24 Sep 2018
    Draft version September 26, 2018 Typeset using LATEX twocolumn style in AASTeX62 2018 Census of Interstellar, Circumstellar, Extragalactic, Protoplanetary Disk, and Exoplanetary Molecules Brett A. McGuire1, 2, ∗ 1National Radio Astronomy Observatory, Charlottesville, VA 22903, USA 2Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA ABSTRACT To date, 204 individual molecular species, comprised of 16 different elements, have been detected in the interstellar and circumstellar medium by astronomical observations. These molecules range in size from two atoms to seventy, and have been detected across the electromagnetic spectrum from cm- wavelengths to the ultraviolet. This census presents a summary of the first detection of each molecular species, including the observational facility, wavelength range, transitions, and enabling laboratory spectroscopic work, as well as listing tentative and disputed detections. Tables of molecules detected in interstellar ices, external galaxies, protoplanetary disks, and exoplanetary atmospheres are provided. A number of visual representations of this aggregate data are presented and briefly discussed in context. Keywords: Astrochemistry, ISM: molecules 1. INTRODUCTION At shorter wavelengths, the presence of the uniden- Since the detection of the methylidyne (CH), the first tified infrared emission bands (UIRs) – sharp, dis- molecule identified in the interstellar medium (ISM) tinct emission features ubiquitous in ultraviolet (UV)- (Swings & Rosenfeld 1937; Dunham 1937; McKellar irradiated regions in our galaxy as well as seen in dozens 1940), observations of molecules have played crucial of external galaxies – continues to elude conclusive roles in a wide range of applications, from broaden- molecular identification. A substantial body of litera- ing our understanding of interstellar chemical evolution ture now seems to favor the assignment of these emission (Herbst & van Dishoeck 2009) and the formation of features to polyclic aromatic hydrocarbons (PAHs) (Tie- 2 planets (Öberg et al.
    [Show full text]
  • Alberta Ambient Air Quality Objectives: Acrylonitrile
    ALBERTA AMBIENT AIR QUALITY OBJECTIVES AAACCCRRRYYYLLLOOONNNIIITTTRRRIIILLLEEE Characteristics Acrylonitrile (CAS No. 107-13-11), a volatile and flammable gas, is a colourless to slightly yellow liquid at ambient temperature and pressure. Its odour has been described as sweet and faintly pungent, resembling that of peach seeds, onion and garlic, or mustard. Acrylonitrile is used primarily in the fabrication of acrylic fiber, resins, rubbers and elastomers. Emissions of acrylonitrile from the industrial facilities in Alberta have been below the criteria for reporting to the National Pollutant Release Inventory. Since the half-life is of the order of days, acrylonitrile may disperse from the source areas. In the atmosphere it undergoes a photochemical reaction with hydroxyl radicals and produces mainly formaldehyde and, in lesser amounts, other compounds such as formic acid, formyl cyanide, carbon monoxide, and hydrogen cyanide. The detection limit for measurements in ambient air is 0.5 ppb by the US Environmental Protection Agency Compendium Method TO15-A. Effects No published literature could be found on the direct effects of acrylonitrile exposure to terrestrial plants (WBK & Associates Inc., 2002). The primary pathway of acrylonitrile exposure for the general public and animals is through inhalation. Adverse human health responses, including eye and throat irritation, central nervous system effects (e.g. headaches, nausea, vomiting, convulsions and unconsciousness) and death, have been reported in humans after accidental acute exposure via inhalation and/or skin contact. However, corresponding dose (exposure concentrations and durations) associated with these events are not known with a great deal of certainty. Animal studies indicate that at concentrations from 58 to 1,330 mg m-3 (26 to 600 ppm), over exposure durations from 4 hours to 60 hours (on an intermittent basis), acute, short-term exposures of acrylonitrile cause salivation, tearing of the eyes, diarrhea, gastrointestinal injury, seizures, and death.
    [Show full text]
  • Acrylonitrile Fact Sheet 051905 Final AQDB
    Acrylonitrile Fact Sheet WHAT IS ACRYLONITRILE ? Also known as: 2-propenenitrile, vinyl cyanide, cyanoethylene Chemical formula and structure: C 3H3N Physical properties : colorless to pale yellow liquid, with a garlic- or onion-like odor Chemical properties: volatile, flammable liquid (explosive if exposed to flame), soluble in water and most organic solvents; reactive, polymerizes spontaneously with heat or strong alkali. CAS #: 107-13-1. Uses: Used extensively in the manufacture of acrylic and modacrylic fibers (fabrics used in textiles), acrylonitrile-butadiene-styrene (plastics used in business machines, luggage, and construction material), styrene-acrylonitrile (plastics used in automotive and household goods, and in packaging material), and adiponitrile (a chemical used to make nylon). A mixture of acrylonitrile and carbon tetrachloride was used as a pesticide in the past; however, all pesticide uses have stopped . WHERE DOES ACRYLONITRILE COME FROM ? Sources: Acrylonitrile does not occur naturally. Sources of release of acrylonitrile to the environment include fugitive emissions from facilities producing, processing, and using the chemical in the manufacture of acrylic and modacrylic fibers, resins, adiponitrile, acrylamide, and other resins and chemicals. Other sources of acrylonitrile include landfills, cigarette smoke, auto exhaust, and the incineration of sewage sludge. It may also be released from polyacrylic fibers and plastics. What is the statewide inventory for acrylonitrile? Approximately 170,000 pounds of acrylonitrile were emitted into the air in California in 2002. Acrylonitrile is a product of incomplete combustion and is emitted from cars and trucks (mobile sources). Acrylonitrile is also emitted directly from stationary sources. According to our estimates, the most significant stationary sources are landfills (46%), the chemical industry (33%), other industrial processes (10%), and petroleum marketing (7%).
    [Show full text]