Benzene and Its Derivatives
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Common Names for Selected Aromatic Groups
More Nomenclature: Common Names for Selected Aromatic Groups Phenyl group = or Ph = C6H5 = Aryl = Ar = aromatic group. It is a broad term, and includes any aromatic rings. Benzyl = Bn = It has a -CH2- (methylene) group attached to the benzene ring. This group can be used to name particular compounds, such as the one shown below. This compound has chlorine attached to a benzyl group, therefore it is called benzyl chloride. Benzoyl = Bz = . This is different from benzyl group (there is an extra “o” in the name). It has a carbonyl attached to the benzene ring instead of a methylene group. For example, is named benzoyl chloride. Therefore, it is sometimes helpful to recognize a common structure in order to name a compound. Example: Nomenclature: 3-phenylpentane Example: This is Amaize. It is used to enhance the yield of corn production. The systematic name for this compound is 2,4-dinitro-6-(1-methylpropyl)phenol. Polynuclear Aromatic Compounds Aromatic rings can fuse together to form polynuclear aromatic compounds. Example: It is two benzene rings fused together, and it is aromatic. The electrons are delocalized in both rings (think about all of its resonance form). Example: This compound is also aromatic, including the ring in the middle. All carbons are sp2 hybridized and the electron density is shared across all 5 rings. Example: DDT is an insecticide and helped to wipe out malaria in many parts of the world. Consequently, the person who discovered it (Muller) won the Nobel Prize in 1942. The systematic name for this compound is 1,1,1-trichloro-2,2-bis-(4-chlorophenyl)ethane. -
Review of Market for Octane Enhancers
May 2000 • NREL/SR-580-28193 Review of Market for Octane Enhancers Final Report J.E. Sinor Consultants, Inc. Niwot, Colorado National Renewable Energy Laboratory 1617 Cole Boulevard Golden, Colorado 80401-3393 NREL is a U.S. Department of Energy Laboratory Operated by Midwest Research Institute • Battelle • Bechtel Contract No. DE-AC36-99-GO10337 May 2000 • NREL/SR-580-28193 Review of Market for Octane Enhancers Final Report J.E. Sinor Consultants, Inc. Niwot, Colorado NREL Technical Monitor: K. Ibsen Prepared under Subcontract No. TXE-0-29113-01 National Renewable Energy Laboratory 1617 Cole Boulevard Golden, Colorado 80401-3393 NREL is a U.S. Department of Energy Laboratory Operated by Midwest Research Institute • Battelle • Bechtel Contract No. DE-AC36-99-GO10337 NOTICE This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States government or any agency thereof. Available electronically at http://www.doe.gov/bridge Available for a processing fee to U.S. -
Formation of Highly Oxygenated Organic Molecules from Aromatic Compounds
Formation of highly oxygenated organic molecules from aromatic compounds. Ugo Molteni1, Federico Bianchi1-2, Felix Klein1, Imad El Haddad1, Carla Frege1, Michel J. Rossi1, Josef Dommen1, Urs Baltensperger1,* 5 1Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, CH-5232 Villigen, Switzerland 2Department of Physics, University of Helsinki, 00014 Helsinki, Finland Correspondence to: Urs Baltensperger ([email protected]) Abstract 10 Anthropogenic volatile organic compounds (AVOC) often dominate the urban atmosphere and consist to a large degree of aromatic hydrocarbons (ArHC), such as benzene, toluene, xylenes, and trimethylbenzenes, e.g. from handling and combustion of fuels. These compounds are important precursors for the formation of secondary organic aerosol. Despite their recognized importance as atmospheric reactants, the formation of highly oxygenated molecules (HOMs) in the gas phase leading to (extremely) low volatility compounds has not been studied in the past. Here we show that oxidation of 15 aromatics with OH leads to a subsequent autoxidation chain reaction forming HOMs with an O:C ratio of up to 1.09. This is exemplified for five single-ring ArHC (benzene, toluene, o-/m-/p-xylene, mesitylene (1,3,5-trimethylbenzene) and ethylbenzene), as well as two conjugated polycyclic ArHC (naphthalene and biphenyl). We present the identified compounds, differences in the observed oxidation patterns and discuss mechanistic pathways. We report the elemental composition of the HOMs and show the differences in the oxidation patterns of these ArHCs. A potential pathway for the 20 formation of these HOMs from aromatics is presented and discussed. We hypothesize that AVOC may contribute substantially to new particle formation events that have been detected in urban areas. -
Zr-Modified Zno for the Selective Oxidation of Cinnamaldehyde to Benzaldehyde
catalysts Article Zr-Modified ZnO for the Selective Oxidation of Cinnamaldehyde to Benzaldehyde Pengju Du 1, Tongming Su 1, Xuan Luo 1, Xinling Xie 1, Zuzeng Qin 1,* and Hongbing Ji 1,2 1 School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China 2 School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China * Correspondence: [email protected]; Tel.: +86-771-323-3718 Received: 31 July 2019; Accepted: 21 August 2019; Published: 25 August 2019 Abstract: ZnO and Zr-modified ZnO were prepared using a precipitation method and used for the selective oxidation of cinnamaldehyde to benzaldehyde in the present study. The results showed that physicochemical properties of ZnO were significantly affected by the calcination temperature, and calcination of ZnO at 400 ◦C demonstrated the optimum catalytic activity for the selective oxidation of cinnamaldehyde to benzaldehyde. With 0.01 g ZnO calcined at 400 ◦C for 2 h as a catalyst, 8.0 g ethanol and 2.0 g cinnamaldehyde reacted at an oxygen pressure of 1.0 MPa and 70 ◦C for 60 min, resulting in benzaldehyde selectivity of 69.2% and cinnamaldehyde conversion of 16.1%. Zr was the optimal modifier for ZnO: when Zr-modified ZnO was used as the catalyst, benzaldehyde selectivity reached 86.2%, and cinnamaldehyde conversion was 17.6%. The X-ray diffractometer and N2 adsorption–desorption characterization indicated that doping with Zr could reduce the crystallite size of ZnO (101) and increase the specific surface area of the catalyst, which provided more active sites for the reaction. X-ray photoelectron spectrometer results showed that Zr-doping could exchange the electrons with ZnO and reduce the electron density in the outer layer of Zn, which would further affect benzaldehyde selectivity. -
Including Toluene Derivatives
RSC Advances View Article Online PAPER View Journal | View Issue Catalytic C–H aerobic and oxidant-induced oxidation of alkylbenzenes (including toluene Cite this: RSC Adv., 2020, 10,23543 derivatives) over VO2+ immobilized on core–shell Fe3O4@SiO2 at room temperature in water† Pegah Mohammadpour and Elham Safaei * Direct C–H bond oxidation of organic materials, and producing the necessary oxygenated compounds under mild conditions, has attracted increasing interest. The selective oxidation of various alkylbenzenes 2+ was carried out by means of a new catalyst containing VO species supported on silica-coated Fe3O4 nanoparticles using t-butyl hydroperoxide as an oxidant at room temperature in H2O or solvent-free media. The chemical and structural characterization of the catalyst using several methods such as FTIR spectroscopy, XRD, FETEM, FESEM, SAED, EDX and XPS showed that VO2+ is covalently bonded to the silica surface. High selectivity and excellent conversion of various toluene derivatives, with less reactive Creative Commons Attribution 3.0 Unported Licence. Received 18th April 2020 aliphatic (sp3)C–H bonds, to related benzoic acids were quite noticeable. The aerobic oxygenation Accepted 15th May 2020 reaction of these alkylbenzenes was studied under the same conditions. All the results accompanied by DOI: 10.1039/d0ra03483e sustainability of the inexpensive and simple magnetically separable heterogeneous catalyst proved the rsc.li/rsc-advances important criteria for commercial applications. Introduction industrial communities. Among -
Fischer Carbene Complexes in Organic Synthesis Ke Chen 1/31/2007
Baran Group Meeting Fischer Carbene Complexes in Organic Synthesis Ke Chen 1/31/2007 Ernst Otto Fischer (1918 - ) Other Types of Stabilized Carbenes: German inorganic chemist. Born in Munich Schrock carbene, named after Richard R. Schrock, is nucleophilic on November 10, 1918. Studied at Munich at the carbene carbon atom in an unpaired triplet state. Technical University and spent his career there. Became director of the inorganic Comparision of Fisher Carbene and Schrock carbene: chemistry institute in 1964. In the 1960s, discovered a metal alkylidene and alkylidyne complexes, referred to as Fischer carbenes and Fischer carbynes. Shared the Nobel Prize in Chemistry with Geoffery Wilkinson in 1973, for the pioneering work on the chemistry of organometallic compounds. Schrock carbenes are found with: Representatives: high oxidation states Isolation of first transition-metal carbene complex: CH early transition metals Ti(IV), Ta(V) 2 non pi-acceptor ligands Cp2Ta CH N Me LiMe Me 2 2 non pi-donor substituents CH3 (CO) W CO (CO)5W 5 (CO)5W A.B. Charette J. Am. Chem. Soc. 2001, 123, 11829. OMe O E. O. Fischer, A. Maasbol, Angew. Chem. Int. Ed., 1964, 3, 580. Persistent carbenes, isolated as a crystalline solid by Anthony J. Arduengo in 1991, can exist in the singlet state or the triplet state. Representative Fischer Carbenes: W(CO) Cr(CO) 5 5 Fe(CO)4 Mn(CO)2(MeCp) Co(CO)3SnPh3 Me OMe Ph Ph Ph NEt2 Ph OTiCp2Cl Me OMe Foiled carbenes were defined as "systems where stabilization is Fischer carbenes are found with : obtained by the inception of the facile reaction which is foiled by the impossibility of attaining the final product geometry". -
Introduction to Aromaticity
Introduction to Aromaticity Historical Timeline:1 Spotlight on Benzene:2 th • Early 19 century chemists derive benzene formula (C6H6) and molecular mass (78). • Carbon to hydrogen ratio of 1:1 suggests high reactivity and instability. • However, benzene is fairly inert and fails to undergo reactions that characterize normal alkenes. - Benzene remains inert at room temperature. - Benzene is more resistant to catalytic hydrogenation than other alkenes. Possible (but wrong) benzene structures:3 Dewar benzene Prismane Fulvene 2,4- Hexadiyne - Rearranges to benzene at - Rearranges to - Undergoes catalytic - Undergoes catalytic room temperature. Faraday’s benzene. hydrogenation easily. hydrogenation easily - Lots of ring strain. - Lots of ring strain. - Lots of ring strain. 1 Timeline is computer-generated, compiled with information from pg. 594 of Bruice, Organic Chemistry, 4th Edition, Ch. 15.2, and from Chemistry 14C Thinkbook by Dr. Steven Hardinger, Version 4, p. 26 2 Chemistry 14C Thinkbook, p. 26 3 Images of Dewar benzene, prismane, fulvene, and 2,4-Hexadiyne taken from Chemistry 14C Thinkbook, p. 26. Kekulé’s solution: - “snake bites its own tail” (4) Problems with Kekulé’s solution: • If Kekulé’s structure were to have two chloride substituents replacing two hydrogen atoms, there should be a pair of 1,2-dichlorobenzene isomers: one isomer with single bonds separating the Cl atoms, and another with double bonds separating the Cl atoms. • These isomers were never isolated or detected. • Rapid equilibrium proposed, where isomers interconvert so quickly that they cannot be isolated or detected. • Regardless, Kekulé’s structure has C=C’s and normal alkene reactions are still expected. - But the unusual stability of benzene still unexplained. -
On the Harmonic Oscillator Model of Electron Delocalization (HOMED) Index and Its Application to Heteroatomic Π-Electron Systems
Symmetry 2010, 2, 1485-1509; doi:10.3390/sym2031485 OPEN ACCESS symmetry ISSN 2073-8994 www.mdpi.com/journal/symmetry Article On the Harmonic Oscillator Model of Electron Delocalization (HOMED) Index and its Application to Heteroatomic π-Electron Systems Ewa D. Raczyñska 1, *, Małgorzata Hallman 1, Katarzyna Kolczyñska 2 and Tomasz M. Stêpniewski 2 1 Department of Chemistry, Warsaw University of Life Sciences (SGGW), ul. Nowoursynowska 159c, 02-776 Warszawa, Poland 2 Interdisciplinary Department of Biotechnology, Warsaw University of Life Sciences (SGGW), ul. Nowoursynowska 166, 02-776 Warszawa, Poland * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +48-22-59-37623; Fax: +49-22-59-37635. Received: 23 April 2010; in revised form: 19 May 2010 / Accepted: 7 July 2010 / Published: 12 July 2010 Abstract: The HOMA (Harmonic Oscillator Model of Aromaticity) index, reformulated in 1993, has been very often applied to describe π-electron delocalization for mono- and polycyclic π-electron systems. However, different measures of π-electron delocalization were employed for the CC, CX, and XY bonds, and this index seems to be inappropriate for compounds containing heteroatoms. In order to describe properly various resonance effects (σ-π hyperconjugation, n-π conjugation, π-π conjugation, and aromaticity) possible for heteroatomic π-electron systems, some modifications, based on the original HOMA idea, were proposed and tested for simple DFT structures containing C, N, and O atoms. An abbreviation HOMED was used for the modified index. Keywords: geometry-based index; π -electron delocalization; σ - π hyperconjugation; n-π conjugation; π-π conjugation; aromaticity; heteroatomic compounds; DFT 1. -
REGISTRY Database Summary Sheet (DBSS)
SM REGISTRY/ZREGISTRY (CAS REGISTRY ) Subject • All types of inorganic and organic substances, including alloys, coordination Coverage compounds, minerals, mixtures, polymers, salts, high throughput screening (HTS) compounds as well as nucleic acid and protein sequences • Substances included in REGISTRY meet the following criteria: - Identified by CAS as coming from a reputable source, including but not limited to patents, journals, chemical catalogs, and selected substance collections on the web - Described in largely unambiguous terms - Characterized by physical methods or described in a patent document example or claim - Consistent with the laws of atomic covalent organization • Experimental and predicted property data and tags and spectra data File Type Numeric, Structure Features Alerts (SDIs) Biweekly In addition, SMARTracker, an automatic crossfile current-awareness search, (SDI XFILE) using a REGISTRY search profile in CA, HCA, ZCA, CAplus, HCAplus or ZCAplus may be run weekly or biweekly (weekly is the default). CAS Registry Keep & Share SLART Number® Identifiers ® Learning Database STN Easy Structures Record • CAS Registry Numbers • Experimental and predicted property Content • CA index names and commonly used data and tags chemical names and trade names • Spectra • Molecular formulas • List of databases and regulatory listings • Structure diagrams containing information on the substances • Sequence data • Super roles and document type SM • Alloy composition tables information from CAplus • Classes for polymers • Displayable information for 10 most recent references for substances • Ring analysis data File Size More than 140 million organic and inorganic substances; more than 71.1 million sequences (4/18) Coverage Early 1800s to the present Updates Daily Language English Database Chemical Abstracts Service Producer 2540 Olentangy River Road P.O. -
Reactions of Benzene Or Alkylbenzenes with Steam Over a Silica-Supported Nickel Catalyst*
54 Reactions of Benzene or Alkylbenzenes with Steam over a Silica-supported Nickel Catalyst* by .Masahiro Saito**, Yoshio Sohda** Michiaki Tokuno** and Yoshiro Morita** Summary: Benzene-steam and alkylbenzenes-steam reactions over a silica-supported nickel catalyst have been studied under atmospheric pressure in a temperature range of 370~430℃. In the reactionof benzene-steam,the methaneyield is lower and the carbon dioxideyield is higher than the estimatedvalue. The reactionis zero order with respectto benzeneand approxi- mately first order with respect to steam. In the reactionof alkylbenzenes-steam,ring breakdownand dealkylationoccur at the initial stage of reaction, and theformer occursmore easily than the latter at high conversionand at high temperature. The number and the position of the alkyl group on the benzene ring influencethe reaction rate and the selectivity. The reactionpath of dealkylationis proposed as follows: most effective catalyst for dealkylation with 1 Introduction steam, and they investigated reactivity and reac- The catalytic reaction of hydrocarbon with tion path on Ni/BeO at 450℃. steam is important for the production of hydrogen, In the present work, the reactions of benzene synthesis gas and town gas. The authors have or alkylbenzenes with steam were carried out previously reported the works on olefins-steam over a silica-supported nickel catalyst under and paraffins-steam reactions over a silica-sup- atmospheric pressure in a temperature range of ported nickel catalyst1)~3), and this study on 370~430℃, and the effects of reaction conditions, aromatics-steam reactions has been carried out rate of each reaction and the reaction path were as a consecutive one. -
Chemistry 0310 - Organic Chemistry 1 Chapter 3
Dr. Peter Wipf Chemistry 0310 - Organic Chemistry 1 Chapter 3. Reactions of Alkanes The heterolysis of covalent bonds yields anions and cations, whereas the homolysis creates radicals. Radicals are species with unpaired electrons that react mostly as electrophiles, seeking a single electron to complete their octet. Free radicals are important reaction intermediates and are formed in initiation reactions under conditions that cause the homolytic cleavage of bonds. In propagation steps, radicals abstract hydrogen or halogen atoms to create new radicals. Combinations of radicals are rare due to the low concentration of these reactive intermediates and result in termination of the radical chain. !CHAIN REACTION SUMMARY reactant product initiation PhCH3 HCl Cl 2 h DH = -16 kcal/mol chain-carrying intermediates n o r D (low concentrations) PhCH2 . Cl . propagation PhCH2 . or Cl . PhCH . 2 DH = -15 kcal/mol or Cl . PhCH2Cl or PhCH CH Ph PhCH2Cl Cl2 2 2 PhCH2Cl or Cl2 termination product reactant termination Alkanes are converted to alkyl halides by free radical halogenation reactions. The relative stability of radicals is increased by conjugation and hyperconjugation: R H H H . CH2 > R C . > R C . > H C . > H C . R R R H Oxygen is a diradical. In the presence of free-radical initiators such as metal salts, organic compounds and oxygen react to give hydroperoxides. These autoxidation reactions are responsible for the degradation reactions of oils, fatty acids, and other biological substances when exposed to air. Antioxidants such as hindered phenols are important food additives. Vitamins E and C are biological antioxidants. Radical chain reactions of chlorinated fluorocarbons in the stratosphere are responsible for the "ozone hole". -
Reduction of Organic Functional Groups Using Hypophosphites Rim Mouselmani
Reduction of Organic Functional Groups Using Hypophosphites Rim Mouselmani To cite this version: Rim Mouselmani. Reduction of Organic Functional Groups Using Hypophosphites. Other. Univer- sité de Lyon; École Doctorale des Sciences et de Technologie (Beyrouth), 2018. English. NNT : 2018LYSE1241. tel-02147583v2 HAL Id: tel-02147583 https://tel.archives-ouvertes.fr/tel-02147583v2 Submitted on 5 Jun 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. THESE de DOCTORAT DE L’UNIVERSITE DE LYON EN COTUTELLE AVEC L'UNIVERSITÉ LIBANAISE opérée au sein de l’Université Claude Bernard Lyon 1 École Doctorale de Chimie-École Doctorale des Sciences et Technologies Discipline : Chimie Soutenue publiquement le 07/11/2018, par Rim MOUSELMANI Reduction of Organic Functional Groups Using Hypophosphites Devant le jury composé de Mme. Micheline DRAYE Université Savoie Mont Blanc Rapporteure M. Mohammad ELDAKDOUKI Université Arabe de Beyrouth Rapporteur Mme. Emmanuelle SCHULZ Université Paris 11 examinatrice M. Abderrahmane AMGOUNE Université Lyon 1 Président M. Mahmoud FARAJ Université Internationale Libanaise examinateur Mme. Estelle MÉTAY Université Lyon 1 Directrice de thèse M. Ali HACHEM Université Libanaise Directeur de thèse M. Marc LEMAIRE Université Lyon 1 Membre invité M.