Structural Isomers – Just How Many Structures Can You Make from a Simple Formula?
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Use of Solvents for Pahs Extraction and Enhancement of the Pahs Bioremediation in Coal- Tar-Contaminated Soils Pak-Hing Lee Iowa State University
Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 2000 Use of solvents for PAHs extraction and enhancement of the PAHs bioremediation in coal- tar-contaminated soils Pak-Hing Lee Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Environmental Engineering Commons Recommended Citation Lee, Pak-Hing, "Use of solvents for PAHs extraction and enhancement of the PAHs bioremediation in coal-tar-contaminated soils " (2000). Retrospective Theses and Dissertations. 13912. https://lib.dr.iastate.edu/rtd/13912 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter fece, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quaiity of the copy submitted. Broken or indistinct print colored or poor quality illustrations and photographs, print bleedthrough, substeindard margins, and improper alignment can adversely affect reproduction. In the unlilcely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. -
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. -
Cyclobutane Derivatives in Drug Discovery
Cyclobutane Derivatives in Drug Discovery Overview Key Points Unlike larger and conformationally flexible cycloalkanes, Cyclobutane adopts a rigid cyclobutane and cyclopropane have rigid conformations. Due to the ring strain, cyclobutane adopts a rigid puckered puckered conformation Offer ing advantages on (~30°) conformation. This unique architecture bestowed potency, selectivity and certain cyclobutane-containing drugs with unique pharmacokinetic (PK) properties. When applied appropriately, cyclobutyl profile. scaffolds may offer advantages on potency, selectivity and pharmacokinetic (PK) profile. Bridging Molecules for Innovative Medicines 1 PharmaBlock designs and Cyclobutane-containing Drugs synthesizes over 1846 At least four cyclobutane-containing drugs are currently on the market. cyclobutanes, and 497 Chemotherapy carboplatin (Paraplatin, 1) for treating ovarian cancer was cyclobutane products are prepared to lower the strong nephrotoxicity associated with cisplatin. By in stock. CLICK HERE to replacing cisplatin’s two chlorine atoms with cyclobutane-1,1-dicarboxylic find detailed product acid, carboplatin (1) has a much lower nephrotoxicity than cisplatin. On information on webpage. the other hand, Schering-Plough/Merck’s hepatitis C virus (HCV) NS3/4A protease inhibitor boceprevir (Victrelis, 2) also contains a cyclobutane group in its P1 region. It is 3- and 19-fold more potent than the 1 corresponding cyclopropyl and cyclopentyl analogues, respectively. Androgen receptor (AR) antagonist apalutamide (Erleada, 4) for treating castration-resistant prostate cancer (CRPC) has a spirocyclic cyclobutane scaffold. It is in the same series as enzalutamide (Xtandi, 3) discovered by Jung’s group at UCLA in the 2000s. The cyclobutyl- (4) and cyclopentyl- derivative have activities comparable to the dimethyl analogue although the corresponding six-, seven-, and eight-membered rings are slightly less 2 active. -
Stereochemistry, Alkyl Halide Substitution (SN1 & SN2)
Chem 261 Assignment & Lecture Outline 3: Stereochemistry, Alkyl Halide Substitution (SN1 & SN2) Read Organic Chemistry, Solomons, Fryle & Snyder 12th Edition (Electronic) • Functional Group List – Learn to recognize – Please see Green Handout – also p 76 of text • Periodic Table – Inside Front Cover - know 1st 10 elements (up through Neon) • Relative Strength of Acids and Bases – Inside Front cover (reference only) • Chapter 5 – Stereochemistry • Chapter 6 –Ionic Reactions: Nucleophilic Substitution of Alkyl Halides Problems: Do Not turn in, answers available in "Study Guide Student Solutions Manual " Solomons, Fryle, Snyder • Chapter 5: 5.1 to 5.15; 5.18 to 5.21; 5.26; 5.28; 5.33a-d; 5.46 • Chapter 6: 6.1 to 6.5; 6.7 to 6.10; 6.13; 6.20; 6.26; 6.27 Lecture Outline # 3 I. Comparison of 2 Structures: Same Molecular Formula ? -> If Yes, Possibly Isomers or Identical Same Arrangement (Sequence) of Groups ? If No -> Structural Isomers If Yes -> Superposable? If Yes -> Identical Structures If No -> Stereoisomers Non-Superposable Mirror Images ? If NO -> Diastereomers If Yes -> Enantiomers II. Chirality and Stereoisomers A. The Concept of Chirality 1. Identification of chiral objects a) achiral = not chiral b) planes of symmetry within a molecule 2. Types of stereoisomers – enantiomers and diastereomers B. Location of stereogenic (chiral) centres – 4 different groups on tetrahedral atom 1. Enantiomers & diastereomers 2. Meso compounds - chiral centers with plane of symmetry within molecule 3. Molecules with more than one chiral centre 4. Recognition of chiral centers in complex molecules - cholesterol - 8 chiral centres Drawing the enantiomer of cholesterol and its potential 255 stereoisomers 5. -
Supporting Information of Polycyclic Aromatic Hydrocarbons (Pahs) In
Supporting Information of Polycyclic aromatic hydrocarbons (PAHs) in aerosols over the central Himalayas along two south-north transects Peng Fei Chen1,5, Chao Liu Li1, Shi Chang Kang2,3*, Maheswar Rupakheti4, Arnico K Panday6, Fang Ping Yan2,5, Quan Lian Li2, Qiang Gong Zhang1,3, Jun Ming Guo1,5, Dipesh Rupakheti1,5, Wei Luo7 1Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China 2State Key Laboratory of Cryospheric Science, Cold and Arid Regions Environmental and Engineering Research Institute, Lanzhou 730000, China 3Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100085, China; 4Institute for Advanced Sustainability Studies, Potsdam 14467, Germany 5University of Chinese Academy of Sciences, Beijing 100039, China 6International Centre for Integrated Mountain Development, Kathmandu, Nepal 7State Key Lab of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China Correspondence to: S. Kang ([email protected]) Text SI-1 Sample extraction and analysis Text SI-2 Quality control Table SI-1 Percentage contribution (%) of each species to total PAHs in the atmosphere over the Himalayas. Text SI-1 Sample extraction and analysis A quarter of each filter was cut into pieces, placed into a glass tube, and immersed in 20 mL of dichloromethane (DCM) and n-hexane (1:1). The extraction was performed by sonication twice for 30 min at 27 °C. Every single sample was spiked with deuterated PAHs (naphthalene-d8, acenaphthene-d10, phenanthrene-d10, chrysene-d12, and perylene-d12) as recovery surrogates. -
Isomer Distributions of Molecular Weight 247 and 273 Nitro-Pahs in Ambient Samples, NIST Diesel SRM, and from Radical-Initiated Chamber Reactions
Atmospheric Environment 55 (2012) 431e439 Contents lists available at SciVerse ScienceDirect Atmospheric Environment journal homepage: www.elsevier.com/locate/atmosenv Isomer distributions of molecular weight 247 and 273 nitro-PAHs in ambient samples, NIST diesel SRM, and from radical-initiated chamber reactions Kathryn Zimmermann a,1, Roger Atkinson a,1,2,3, Janet Arey a,1,2,*, Yuki Kojima b,4, Koji Inazu b,5 a Air Pollution Research Center, University of California, Riverside, CA 92521, USA b Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan article info abstract Article history: Molecular weight (mw) 247 nitrofluoranthenes and nitropyrenes and mw 273 nitrotriphenylenes (NTPs), Received 27 December 2011 nitrobenz[a]anthracenes, and nitrochrysenes were quantified in ambient particles collected in Riverside, Received in revised form CA, Tokyo, Japan, and Mexico City, Mexico. 2-Nitrofluoranthene (2-NFL) was the most abundant nitro- 28 February 2012 polycyclic aromatic hydrocarbon (nitro-PAH) in Riverside and Mexico City, and the mw 273 nitro-PAHs Accepted 5 March 2012 were observed in lower concentrations. However, in Tokyo concentrations of 1- þ 2-NTP were more similar to that of 2-NFL. NIST SRM 1975 diesel extract standard reference material was also analyzed to Keywords: examine nitro-PAH isomer distributions, and 12-nitrobenz[a]anthracene was identified for the first time. Nitro-PAH fl Atmospheric reactions The atmospheric formation pathways of nitro-PAHs were studied from chamber reactions of uo- Ambient particles ranthene, pyrene, triphenylene, benz[a]anthracene, and chrysene with OH and NO3 radicals at room Nitrotriphenylenes temperature and atmospheric pressure, with the PAH concentrations being controlled by their vapor pressures. -
Recent Advances in the Total Synthesis of Cyclobutane-Containing Natural Products Cite This: Org
Volume 7 | Number 1 | 7 January 2020 ORGANIC CHEMISTRY FRONTIERS rsc.li/frontiers-organic ORGANIC CHEMISTRY FRONTIERS View Article Online REVIEW View Journal | View Issue Recent advances in the total synthesis of cyclobutane-containing natural products Cite this: Org. Chem. Front., 2020, 7, 136 Jinshan Li,†a Kai Gao, †a Ming Bianb and Hanfeng Ding *a,c Complex natural products bearing strained cyclobutane subunits, including terpenoids, alkaloids and steroids, not only display fascinating architectures, but also show potent biological activities. Due to their unique structures as critical core skeletons in these molecules, a variety of new strategies for the con- Received 24th September 2019, struction of cyclobutane rings have greatly emerged during the last decade. In this review, we wish to Accepted 11th November 2019 summarize the recent progress in the cyclobutane-containing natural product synthesis with an emphasis DOI: 10.1039/c9qo01178a on disconnection tactics employed to forge the four-membered rings, aiming to provide a complement rsc.li/frontiers-organic to existing reviews. 1. Introduction stereoselectively, poses significant challenges in synthetic chemistry. On the other hand, cyclobutanes readily undergo a In the class of strained carbocycles, cyclobutanes have been number of ring-opening reactions by virtue of their tendency known as intriguing structural motifs for more than one to release inherent strain energies. In some cases, however, century but remained relatively less explored in parallel with striking ring strains can be dramatically reduced by the instal- their homologues.1 Due to the highly strained ring systems (ca. lation of a gem-dialkyl substituent (through the Thorpe–Ingold − 26.7 kcal mol 1), construction of cyclobutane rings, especially effect),2 a carbonyl group, a heteroatom, or other functional- ities (Fig. -
Questions & Answers for the New Chemicals Program
Note: Effective January 19, 2016, PMNs must be submitted electronically. Learn more about the new e-PMN requirements. Questions & Answers for the New Chemicals Program (Q&A) U.S. Environmental Protection Agency Office of Pollution Prevention and Toxics Washington, DC 20460 2004 -1- TABLE OF CONTENTS Page 1. GENERAL PROGRAM INFORMATION 100. General ............................................................................................................ 1-1 101. Guidance for Completion of §5 Submission Form ......................................... 1-6 102. Inventory Searches/Bona Fides ....................................................................... 1-17 103. Chemical Identification ................................................................................... 1-22 104. Nomenclature .................................................................................................. 1-26 105. Inventory Issues ................................................................................................ 1-31 106. Review Process ............................................................................................... 1-31 107. Notice of Commencement .............................................................................. 1-33 108. User Fee .......................................................................................................... 1-35 109. Consolidated Notices ...................................................................................... 1-39 110. Joint Submissions .......................................................................................... -
Amide Activation: an Emerging Tool for Chemoselective Synthesis
Featuring work from the research group of Professor As featured in: Nuno Maulide, University of Vienna, Vienna, Austria Amide activation: an emerging tool for chemoselective synthesis Let them stand out of the crowd – Amide activation enables the chemoselective modification of a large variety of molecules while leaving many other functional groups untouched, making it attractive for the synthesis of sophisticated targets. This issue features a review on this emerging field and its application in total synthesis. See Nuno Maulide et al., Chem. Soc. Rev., 2018, 47, 7899. rsc.li/chem-soc-rev Registered charity number: 207890 Chem Soc Rev View Article Online REVIEW ARTICLE View Journal | View Issue Amide activation: an emerging tool for chemoselective synthesis Cite this: Chem. Soc. Rev., 2018, 47,7899 Daniel Kaiser, Adriano Bauer, Miran Lemmerer and Nuno Maulide * It is textbook knowledge that carboxamides benefit from increased stabilisation of the electrophilic carbonyl carbon when compared to other carbonyl and carboxyl derivatives. This results in a considerably reduced reactivity towards nucleophiles. Accordingly, a perception has been developed of amides as significantly less useful functional handles than their ester and acid chloride counterparts. Received 27th April 2018 However, a significant body of research on the selective activation of amides to achieve powerful DOI: 10.1039/c8cs00335a transformations under mild conditions has emerged over the past decades. This review article aims at placing electrophilic amide activation in both a historical context and in that of natural product rsc.li/chem-soc-rev synthesis, highlighting the synthetic applications and the potential of this approach. Creative Commons Attribution 3.0 Unported Licence. -
Effect of Epoxide Content on the Vulcanizate Structure of Silica-Filled Epoxidized Natural Rubber (ENR) Compounds
polymers Article Effect of Epoxide Content on the Vulcanizate Structure of Silica-Filled Epoxidized Natural Rubber (ENR) Compounds Gyeongchan Ryu 1, Donghyuk Kim 1, Sanghoon Song 1, Kiwon Hwang 1, Byungkyu Ahn 2 and Wonho Kim 1,* 1 School of Chemical Engineering, Pusan National University, Busan 46241, Korea; [email protected] (G.R.); [email protected] (D.K.); [email protected] (S.S.); [email protected] (K.H.) 2 Hankook Tire & Technology Co., Ltd., R&D Center, 50 Yuseong-daero 935 beon-gil, Yuseong-gu, Daejeon 34127, Korea; [email protected] * Correspondence: [email protected]; Tel.: +82-51-510-3190 Abstract: The demand for truck–bus radial (TBR) tires with enhanced fuel efficiency has grown in recent years. Many studies have investigated silica-filled natural rubber (NR) compounds to address these needs. However, silica-filled compounds offer inferior abrasion resistance compared to carbon black-filled compounds. Further, the use of NR as a base rubber can hinder silanization and coupling reactions due to interference by proteins and lipids. Improved silica dispersion be achieved without the use of a silane coupling agent by introducing epoxide groups to NR, which serve as silica-affinitive functional groups. Furthermore, the coupling reaction can be promoted by facilitating chemical interaction between the hydroxyl group of silica and the added epoxide groups. Thus, this study evaluated the properties of commercialized NR, ENR-25, and ENR-50 compounds with or without an added silane coupling agent, and the filler–rubber interaction was quantitatively calculated using vulcanizate structure analysis. The increased epoxide content, when the silane coupling agent was not used, improved silica dispersion, abrasion resistance, fuel efficiency, and wet Citation: Ryu, G.; Kim, D.; Song, S.; grip. -
Organic Chemistry Name Formula Isomers Methane CH 1 Ethane C H
Organic Chemistry Organic chemistry is the chemistry of carbon. The simplest carbon molecules are compounds of just carbon and hydrogen, hydrocarbons. We name the compounds based on the length of the longest carbon chain. We then add prefixes and suffixes to describe the types of bonds and any add-ons the molecule has. When the molecule has just single bonds we use the -ane suffix. Name Formula Isomers Methane CH4 1 Ethane C2H6 1 Propane C3H8 1 Butane C4H10 2 Pentane C5H12 3 Hexane C6H14 5 Heptane C7H16 9 Octane C8H18 18 Nonane C9H20 35 Decane C10H22 75 Isomers are compounds that have the same formula but different bonding. isobutane n-butane 1 Naming Alkanes Hydrocarbons are always named based on the longest carbon chain. When an alkane is a substituent group they are named using the -yl ending instead of the -ane ending. So, -CH3 would be a methyl group. The substituent groups are named by numbering the carbons on the longest chain so that the first branching gets the lowest number possible. The substituents are listed alphabetically with out regard to the number prefixes that might be used. 3-methylhexane 1 2 3 4 5 6 6 5 4 3 2 1 Alkenes and Alkynes When a hydrocarbon has a double bond we replace the -ane ending with -ene. When the hydrocarbon has more than three carbon the position of the double bond must be specified with a number. 1-butene 2-butene Hydrocarbons with triple bonds are named basically the same, we replace the -ane ending with -yne. -
Electrophilic Mercuration and Thallation of Benzene and Substituted Benzenes in Trifluoroacetic Acid Solution* (Electrophilic Substitution/Selectivity) GEORGE A
Proc. Natl. Acad. Sci. USA Vol. 74, No. 10, pp. 4121-4125, October 1977 Chemistry Electrophilic mercuration and thallation of benzene and substituted benzenes in trifluoroacetic acid solution* (electrophilic substitution/selectivity) GEORGE A. OLAH, IWAO HASHIMOTOt, AND HENRY C. LINtt Institute of Hydrocarbon Chemistry, Department of Chemistry, University of Southern California, Los Angeles, California 90007; and the Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44101 Contributed by George A. Olah, July 18, 1977 ABSTRACT The mercuration and thallation of benzene and iments at 250 and quenched the mixtures after 5 min, whereas substituted benzenes was studied with mercuric and thallic Brown and Nelson carried out the reaction for 6.5 hr. In sub- trifluoroacetate, respectively, in trifluoroacetic acid. With the in view of the importance of both the mechanistic shortest reaction time (1 sec) at 00, the relative rate of mercu- sequent work, ration of toluene compared to that of benzene was 17.5, with and practical implications of the orientation-rate correlation, the isomer distribution in toluene of: ortho, 17.4%; meta, 5.9%; Brown and McGary (7), carried out a more detailed study of and para, 76.7%. The isomer distribution in toluene varied with the mercuration reaction. They concluded: "A redetermination the reaction time, significantly more at 25° than at 00. The of the isomer distributions and relative rates indicates excellent competitive thallation of benzene and toluene with thallic tri- agreement with the linear relationship of orientation and rel- fluoroacetate in trifluoroacetic acid at 150 showed the relative ative however, that the isomer distri- rate, toluene/benzene, to be 33, with the isomer distribution in rate." They recognized, toluene of: ortho, 9.5%; meta, 5.5%; and para, 85.0%.