Naming Organic Compounds Substituents Longest Carbon Chain
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Brief Guide to the Nomenclature of Organic Chemistry
1 Brief Guide to the Nomenclature of Table 1: Components of the substitutive name Organic Chemistry (4S,5E)-4,6-dichlorohept-5-en-2-one for K.-H. Hellwich (Germany), R. M. Hartshorn (New Zealand), CH3 Cl O A. Yerin (Russia), T. Damhus (Denmark), A. T. Hutton (South 4 2 Africa). E-mail: [email protected] Sponsoring body: Cl 6 CH 5 3 IUPAC Division of Chemical Nomenclature and Structure suffix for principal hept(a) parent (heptane) one Representation. characteristic group en(e) unsaturation ending chloro substituent prefix 1 INTRODUCTION di multiplicative prefix S E stereodescriptors CHEMISTRY The universal adoption of an agreed nomenclature is a key tool for 2 4 5 6 locants ( ) enclosing marks efficient communication in the chemical sciences, in industry and Multiplicative prefixes (Table 2) are used when more than one for regulations associated with import/export or health and safety. fragment of a particular kind is present in a structure. Which kind of REPRESENTATION The International Union of Pure and Applied Chemistry (IUPAC) multiplicative prefix is used depends on the complexity of the provides recommendations on many aspects of nomenclature.1 The APPLIED corresponding fragment – e.g. trichloro, but tris(chloromethyl). basics of organic nomenclature are summarized here, and there are companion documents on the nomenclature of inorganic2 and Table 2: Multiplicative prefixes for simple/complicated entities polymer3 chemistry, with hyperlinks to original documents. An No. Simple Complicated No. Simple Complicated AND overall -
Singlet/Triplet State Anti/Aromaticity of Cyclopentadienylcation: Sensitivity to Substituent Effect
Article Singlet/Triplet State Anti/Aromaticity of CyclopentadienylCation: Sensitivity to Substituent Effect Milovan Stojanovi´c 1, Jovana Aleksi´c 1 and Marija Baranac-Stojanovi´c 2,* 1 Institute of Chemistry, Technology and Metallurgy, Center for Chemistry, University of Belgrade, Njegoševa 12, P.O. Box 173, 11000 Belgrade, Serbia; [email protected] (M.S.); [email protected] (J.A.) 2 Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, P.O. Box 158, 11000 Belgrade, Serbia * Correspondence: [email protected]; Tel.: +381-11-3336741 Abstract: It is well known that singlet state aromaticity is quite insensitive to substituent effects, in the case of monosubstitution. In this work, we use density functional theory (DFT) calculations to examine the sensitivity of triplet state aromaticity to substituent effects. For this purpose, we chose the singlet state antiaromatic cyclopentadienyl cation, antiaromaticity of which reverses to triplet state aromaticity, conforming to Baird’s rule. The extent of (anti)aromaticity was evaluated by using structural (HOMA), magnetic (NICS), energetic (ISE), and electronic (EDDBp) criteria. We find that the extent of triplet state aromaticity of monosubstituted cyclopentadienyl cations is weaker than the singlet state aromaticity of benzene and is, thus, slightly more sensitive to substituent effects. As an addition to the existing literature data, we also discuss substituent effects on singlet state antiaromaticity of cyclopentadienyl cation. Citation: Stojanovi´c,M.; Aleksi´c,J.; Baranac-Stojanovi´c,M. Keywords: antiaromaticity; aromaticity; singlet state; triplet state; cyclopentadienyl cation; substituent Singlet/Triplet State effect Anti/Aromaticity of CyclopentadienylCation: Sensitivity to Substituent Effect. -
Minutes of the IUPAC Chemical Nomenclature and Structure Representation Division (VIII) Committee Meeting Boston, MA, USA, August 18, 2002
Minutes of the IUPAC Chemical Nomenclature and Structure Representation Division (VIII) Committee Meeting Boston, MA, USA, August 18, 2002 Members Present: Dr Stephen Heller, Prof Herbert Kaesz, Prof Dr Alexander Lawson, Prof G. Jeffrey Leigh, Dr Alan McNaught (President), Dr. Gerard Moss, Prof Bruce Novak, Dr Warren Powell (Secretary), Dr William Town, Dr Antony Williams Members Absent: Dr. Michael Dennis, Prof Michael Hess National representatives Present: Prof Roberto de Barros Faria (Brazil) The second meeting of the Division Committee of the IUPAC Division of Chemical Nomenclature and Structure Representation held in the Great Republic Room of the Westin Hotel in Boston, Massachusetts, USA was convened by President Alan McNaught at 9:00 a.m. on Sunday, August 18, 2002. 1.0 President McNaught welcomed the members to this meeting in Boston and offered a special welcome to the National Representative from Brazil, Prof Roberto de Barros Faria. He also noted that Dr Michael Dennis and Prof Michael Hess were unable to be with us. Each of the attendees introduced himself and provided a brief bit of background information. Housekeeping details regarding breaks and lunch were announced and an invitation to a reception from the U. S. National Committee for IUPAC on Tuesday, August 20 was noted. 2.0 The agenda as circulated was approved with the addition of a report from Dr Moss on the activity on his website. 3.0 The minutes of the Division Committee Meeting in Cambridge, UK, January 25, 2002 as posted on the Webboard (http://www.rsc.org/IUPAC8/attachments/MinutesDivCommJan2002.rtf and http://www.rsc.org/IUPAC8/attachments/MinutesDivCommJan2002.pdf) were approved with the following corrections: 3.1 The name Dr Gerard Moss should be added to the members present listing. -
The Relative Rates of Thiol–Thioester Exchange and Hydrolysis for Alkyl and Aryl Thioalkanoates in Water
Orig Life Evol Biosph (2011) 41:399–412 DOI 10.1007/s11084-011-9243-4 PREBIOTIC CHEMISTRY The Relative Rates of Thiol–Thioester Exchange and Hydrolysis for Alkyl and Aryl Thioalkanoates in Water Paul J. Bracher & Phillip W. Snyder & Brooks R. Bohall & George M. Whitesides Received: 14 April 2011 /Accepted: 16 June 2011 / Published online: 5 July 2011 # Springer Science+Business Media B.V. 2011 Abstract This article reports rate constants for thiol–thioester exchange (kex), and for acid- mediated (ka), base-mediated (kb), and pH-independent (kw) hydrolysis of S-methyl thioacetate and S-phenyl 5-dimethylamino-5-oxo-thiopentanoate—model alkyl and aryl thioalkanoates, respectively—in water. Reactions such as thiol–thioester exchange or aminolysis could have generated molecular complexity on early Earth, but for thioesters to have played important roles in the origin of life, constructive reactions would have needed to compete effectively with hydrolysis under prebiotic conditions. Knowledge of the kinetics of competition between exchange and hydrolysis is also useful in the optimization of systems where exchange is used in applications such as self-assembly or reversible binding. For the alkyl thioester S-methyl thioacetate, which has been synthesized in −5 −1 −1 −1 −1 −1 simulated prebiotic hydrothermal vents, ka = 1.5×10 M s , kb = 1.6×10 M s , and −8 −1 kw = 3.6×10 s . At pH 7 and 23°C, the half-life for hydrolysis is 155 days. The second- order rate constant for thiol–thioester exchange between S-methyl thioacetate and 2- −1 −1 sulfonatoethanethiolate is kex = 1.7 M s . -
Chapter 7, Haloalkanes, Properties and Substitution Reactions of Haloalkanes Table of Contents 1
Chapter 7, Haloalkanes, Properties and Substitution Reactions of Haloalkanes Table of Contents 1. Alkyl Halides (Haloalkane) 2. Nucleophilic Substitution Reactions (SNX, X=1 or 2) 3. Nucleophiles (Acid-Base Chemistry, pka) 4. Leaving Groups (Acid-Base Chemistry, pka) 5. Kinetics of a Nucleophilic Substitution Reaction: An SN2 Reaction 6. A Mechanism for the SN2 Reaction 7. The Stereochemistry of SN2 Reactions 8. A Mechanism for the SN1 Reaction 9. Carbocations, SN1, E1 10. Stereochemistry of SN1 Reactions 11. Factors Affecting the Rates of SN1 and SN2 Reactions 12. --Eliminations, E1 and E2 13. E2 and E1 mechanisms and product predictions In this chapter we will consider: What groups can be replaced (i.e., substituted) or eliminated The various mechanisms by which such processes occur The conditions that can promote such reactions Alkyl Halides (Haloalkane) An alkyl halide has a halogen atom bonded to an sp3-hybridized (tetrahedral) carbon atom The carbon–chlorine and carbon– bromine bonds are polarized because the halogen is more electronegative than carbon The carbon-iodine bond do not have a per- manent dipole, the bond is easily polarizable Iodine is a good leaving group due to its polarizability, i.e. its ability to stabilize a charge due to its large atomic size Generally, a carbon-halogen bond is polar with a partial positive () charge on the carbon and partial negative () charge on the halogen C X X = Cl, Br, I Different Types of Organic Halides Alkyl halides (haloalkanes) sp3-hybridized Attached to Attached to Attached -
Nomenclature of Alkanes
Nomenclature of alkanes methane CH4 ethane CH3CH3 propane CH3CH2CH3 butane CH3CH2CH2CH3 pentane CH3CH2CH2CH2CH3 hexane CH3CH2CH2CH2CH2CH3 heptane CH3CH2CH2CH2CH2CH2CH3 octane CH3CH2CH2CH2CH2CH2CH2CH3 nonane CH3CH2CH2CH2CH2CH2CH2CH2CH3 decane CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3 undecane CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH3 dodecane CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH3 Funky groups/alkanes iso- CH3 R isopropyl HC R CH3 isobutane/isobutyl R = CH3/CH2R (4 C’s) R isopentane/isopentyl R = CH2CH3/CH2CH2R (5 C’s) R isohexane/isohexyl R = CH2CH2CH3/CH2CH2R (6 C’s) R neo- CH3 neopentyl H3C C CH2 R R CH3 neopentane R = H (5 C’s) neohaxane/neohexyl R = CH3/CH2R (6 C’s) R 1° primary (n-) 2° secondary (sec-, s-) 3° tertiary (tert-, t-) H C H C H3C 3 3 CH CH2 CH CH2 CH CH2 H C CH H C CH H3C CH3 3 3 3 3 n- often used with strait chain compounds though it is not actually necessary. sec- sec-butyl H the substituent is attached s-butyl to a 2° C of butane (4 C’s) H3C CH2 C R CH3 no other "sec-" group tert- tert-butyl CH3 a substituent is attached to t-butyl the 3° C of a 4 C H3C C R molecule/unit CH3 tert-pentyl CH3 a substituent is attached to t-pentyl the 3° of a 5 C molecule/unit H3C CH2 C R CH3 no other "tert-" group Form of name #-followed by substituent name followed by parent hydrocarbon name • Determine longest continuous chain. o This is the parent hydrocarbon o If compound has two or more chains of the same length, parent hydrocarbon is chain with greatest number of substituents • Cite the name of substituent before the name of the parent hydrocarbon along with the number of the carbon to which it is attached--Substituents are listed in alphabetical order – neglecting prefixes such as di- tri- tert- etc. -
United States Patent [191 [11] Patent Number: 5,070,175 Tsumura Et Al
United States Patent [191 [11] Patent Number: 5,070,175 Tsumura et al. [45] Date of Patent: Dec. 3, 1991 [54] METHOD FOR THE PREPARATION OF AN Primary Examiner-Morton Foelak ORGANOPOLYSILOXANE CONTAINING Attorney, Agent, or Firm-Millen, White & Zelano TETRAFUNCI'IONAL SILOXANE UNITS [57] ABSTRACT [75] Inventors: Hiroshi Tsumura; Kiyoyuki Mutoh, An ef?cient and economically advantageous method is both of Gunma; Kazushi Satoh, proposed for the preparation of an organopolysiloxane Tokyo; Ken-ichi Isobe, Gunma, all of comprising tetrafunctional siloxane units, i.e. Q units, Japan and, typically, monofunctional siloxy units, i.e. M units, [73] Assignee: Shin-Etsu Chemical Co., Ltd., Tokyo, and useful as a reinforcing agent in silicone rubbers. The Japan method comprises the steps of: mixing the reactants for providing the Q and M units, such as ethyl orthosilicate [21] Appl. No.;. 706,148 and trimethyl methoxy silane, in a desired molar ratio; [22] Filed: May 28, 1991 and heating the mixture at a temperature higher by at least 10° C. than the boiling point of the mixture under [30] Foreign Application Priority Data normal pressure in a closed vessel in the presence of May 29, 1990 [JP] Japan ............ .Q .................. .. 2-l39ll9 water and a catalyst such as a sulfonic acid group-con taining compound. In addition to the greatly shortened [51] Int. 01.5 ............................................ .. C08G 77/06 reaction time and remarkably decreased contents of [52] U.S. c1. ...................................... .. 528/12; 528/10; residual alkoxy groups and gelled matter in the product, 528/21; 528/23; 528/34; 528/36 the method is advantageous also in respect of the ab [58] Field of Search .................... -
Nomenclature of Carboxylic Acids • Select the Longest Carbon Chain Containing the Carboxyl Group
Chapter 5 Carboxylic Acids and Esters Carboxylic Acids • Carboxylic acids are weak organic acids which Chapter 5 contain the carboxyl group (RCO2H): Carboxylic Acids and Esters O C O H O RCOOH RCO2H Chapter Objectives: O condensed ways of • Learn to recognize the carboxylic acid, ester, and related functional groups. RCOH writing the carboxyl • Learn the IUPAC system for naming carboxylic acids and esters. group a carboxylic acid C H • Learn the important physical properties of the carboxylic acids and esters. • Learn the major chemical reaction of carboxylic acids and esters, and learn how to O predict the products of ester synthesis and hydrolysis reactions. the carboxyl group • Learn some of the important properties of condensation polymers, especially the polyesters. Mr. Kevin A. Boudreaux • The tart flavor of sour-tasting foods is often caused Angelo State University CHEM 2353 Fundamentals of Organic Chemistry by the presence of carboxylic acids. Organic and Biochemistry for Today (Seager & Slabaugh) www.angelo.edu/faculty/kboudrea 2 Nomenclature of Carboxylic Acids • Select the longest carbon chain containing the carboxyl group. The -e ending of the parent alkane name is replaced by the suffix -oic acid. • The carboxyl carbon is always numbered “1” but the number is not included in the name. • Name the substituents attached to the chain in the Nomenclature of usual way. • Aromatic carboxylic acids (i.e., with a CO2H Carboxylic Acids directly connected to a benzene ring) are named after the parent compound, benzoic acid. O C OH 3 -
Introduction to Alkenes and Alkynes in an Alkane, All Covalent Bonds
Introduction to Alkenes and Alkynes In an alkane, all covalent bonds between carbon were σ (σ bonds are defined as bonds where the electron density is symmetric about the internuclear axis) In an alkene, however, only three σ bonds are formed from the alkene carbon -the carbon thus adopts an sp2 hybridization Ethene (common name ethylene) has a molecular formula of CH2CH2 Each carbon is sp2 hybridized with a σ bond to two hydrogens and the other carbon Hybridized orbital allows stronger bonds due to more overlap H H C C H H Structure of Ethylene In addition to the σ framework of ethylene, each carbon has an atomic p orbital not used in hybridization The two p orbitals (each with one electron) overlap to form a π bond (p bonds are not symmetric about the internuclear axis) π bonds are not as strong as σ bonds (in ethylene, the σ bond is ~90 Kcal/mol and the π bond is ~66 Kcal/mol) Thus while σ bonds are stable and very few reactions occur with C-C bonds, π bonds are much more reactive and many reactions occur with C=C π bonds Nomenclature of Alkenes August Wilhelm Hofmann’s attempt for systematic hydrocarbon nomenclature (1866) Attempted to use a systematic name by naming all possible structures with 4 carbons Quartane a alkane C4H10 Quartyl C4H9 Quartene e alkene C4H8 Quartenyl C4H7 Quartine i alkine → alkyne C4H6 Quartinyl C4H5 Quartone o C4H4 Quartonyl C4H3 Quartune u C4H2 Quartunyl C4H1 Wanted to use Quart from the Latin for 4 – this method was not embraced and BUT has remained Used English order of vowels, however, to name the groups -
Dialogue on the Nomenclature and Classification of Prokaryotes
G Model SYAPM-25929; No. of Pages 10 ARTICLE IN PRESS Systematic and Applied Microbiology xxx (2018) xxx–xxx Contents lists available at ScienceDirect Systematic and Applied Microbiology journal homepage: www.elsevier.de/syapm Dialogue on the nomenclature and classification of prokaryotes a,∗ b Ramon Rosselló-Móra , William B. Whitman a Marine Microbiology Group, IMEDEA (CSIC-UIB), 07190 Esporles, Spain b Department of Microbiology, University of Georgia, Athens, GA 30602, USA a r t i c l e i n f o a b s t r a c t Keywords: The application of next generation sequencing and molecular ecology to the systematics and taxonomy Bacteriological code of prokaryotes offers enormous insights into prokaryotic biology. This discussion explores some major Taxonomy disagreements but also considers the opportunities associated with the nomenclature of the uncultured Nomenclature taxa, the use of genome sequences as type material, the plurality of the nomenclatural code, and the roles Candidatus of an official or computer-assisted taxonomy. Type material © 2018 Elsevier GmbH. All rights reserved. Is naming important when defined here as providing labels Prior to the 1980s, one of the major functions of Bergey’s Manual for biological entities? was to associate the multiple names in current usage with the cor- rect organism. For instance, in the 1948 edition of the Manual, 21 Whitman and 33 names were associated with the common bacterial species now named Escherichia coli and Bacillus subtilis, respectively [5]. When discussing the nomenclature of prokaryotes, we must first This experience illustrates that without a naming system gener- establish the role and importance of naming. -
Linear Alkylbenzene Sulphonate (CAS No
Environmental Risk Assessment LAS Linear Alkylbenzene Sulphonate (CAS No. 68411-30-3) Revised ENVIRONMENTAL Aspect of the HERA Report = February 2013 = 1 1. Contents 2. Executive summary 3. Substance characterisation 3.1 CAS No. and grouping information 3.2 Chemical structure and composition 3.3 Manufacturing route and production/volume statistics 3.4 Consumption scenario in Europe 3.5 Use application summary 4. Environmental safety assessment 4.1 Environmental exposure assessment 4.1.1 Biotic and abiotic degradability 4.1.2 Removal 4.1.3 Monitoring studies 4.1.4 Exposure assessment: scenario description 4.1.5 Substance data used for the exposure calculation 4.1.6 PEC calculations 4.1.7 Bioconcentration 4.2 Environmental effects assessment 4.2.1 Ecotoxicity 4.2.1.1 Aquatic ecotoxicity 4.2.1.2 Terrestrial ecotoxicity 4.2.1.3 Sediment ecotoxicity 4.2.1.4 Ecotoxicity to sewage microorganisms 4.2.1.5 Reassurance on absence of estrogenic effects 4.2.2 PNEC calculations 4.2.2.1 Aquatic PNEC 4.2.2.2 Terrestrial PNEC 4.2.2.3 Sludge PNEC 4.2.2.4 Sediment PNEC 4.2.2.5 STP PNEC 4.3 Environment risk assessment 5. 5. References 6. Contributors to the report 6.1 Substance team 6.2 HERA environmental task force 6.3 HERA human health task force 6.4 Industry coalition for the OECD/ICCA SIDS assessment of LAS 2 2. Executive Summary Linear alkylbenzene sulphonate (LAS) is an anionic surfactant. It was introduced in 1964 as the readily biodegradable replacement for highly branched alkylbenzene sulphonates (ABS). -
Marvin Charton - Correlation Analyst Par Excellence
Int. J. Mol. Sci. 2005, 6, 3-10 International Journal of Molecular Sciences ISSN 1422-0067 © 2005 by MDPI www.mdpi.org/ijms/ Marvin Charton - Correlation Analyst Par Excellence John Shorter 29A, Meadowfields, Whitby, North Yorkshire, YO21 1QF, UK. (Emeritus Reader in Chemistry, University of Hull), email: [email protected] Received: 10 September 2004 / Accepted: 19 October 2004 / Published: 31 January 2005 Abstract: Since the late 1950s Marvin Charton, physical organic chemist, of Pratt Institute, Brooklyn, New York has studied structure-property relationships through correlation analysis, and has become one of the leading authorities in this field. Keywords: Hammett equation, correlation analysis, linear free energy relationships, substituent effects and constants, biological activity. Introduction Marvin Charton, of Pratt Institute, Brooklyn, New York, describes his research interests in his CV as follows: "The study of structure-property quantitative relationships in chemistry and biology by means of correlation analysis. Applications of this work include chemical reaction mechanisms, the estimation of chemical and physical properties and chemical reactivities of chemical compounds, the design of bioactive molecules including medicinal drugs and pesticides, and the prediction of environmental toxicities and other properties." His first paper in this field appeared in 1958 and he has now published over 150 research papers and review articles. Marvin's forebears came to the USA from eastern Europe in the late 19th century. His surname may sound French, but his ancestry was Polish, and the relatives who came from Poland to America had the name of Charton. He sometimes suggests, half in fun, that one of his ancestors may have accompanied Napoleon from France to Moscow in 1812, but during the great retreat, by the time they reached Poland he was a little tired of marching, so he absented himself, and found a good place to live and a nice Polish girl to marry...