DOCSLIB.ORG

This Electronic Thesis Or Dissertation Has Been Downloaded from Explore Bristol Research

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
This Electronic Thesis Or Dissertation Has Been Downloaded from Explore Bristol Research This electronic thesis or dissertation has been downloaded from Explore Bristol Research, http://research-information.bristol.ac.uk Author: Hernandez Fajardo, Oscar Title: Mechanistic and Reactivity Studies of First-Row Complexes as Catalysts in Cross- Coupling Reactions. General rights Access to the thesis is subject to the Creative Commons Attribution - NonCommercial-No Derivatives 4.0 International Public License. A copy of this may be found at https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode This license sets out your rights and the restrictions that apply to your access to the thesis so it is important you read this before proceeding. Take down policy Some pages of this thesis may have been removed for copyright restrictions prior to having it been deposited in Explore Bristol Research. However, if you have discovered material within the thesis that you consider to be unlawful e.g. breaches of copyright (either yours or that of a third party) or any other law, including but not limited to those relating to patent, trademark, confidentiality, data protection, obscenity, defamation, libel, then please contact [email protected] and include the following information in your message: •Your contact details •Bibliographic details for the item, including a URL •An outline nature of the complaint Your claim will be investigated and, where appropriate, the item in question will be removed from public view as soon as possible. Mechanistic and Reactivity Studies of First-Row Complexes as Catalysts in Cross-Coupling Reactions. Oscar Hernández Fajardo A thesis submitted to the University of Bristol in accordance with the requirements of the degree of Doctor of Philosophy in the School of Chemistry, Faculty of Science. November 2018 1 Abstract Iron(II) complexes show activity in Negishi cross-coupling reactions. A series of mechanistic studies were conducted using spectroscopic techniques in order to improve the understanding of this reaction. It has been observed that Fe(II) is reduced to Fe(I) species when it interacts with the nucleophilic reagent in the reaction mixture. These reduced species show excellent catalytic activity. A kinetic study was conducted using UV-vis spectroscopy which demonstrates that the presence of Lewis acids and Lewis bases influence the speed of reaction. A free-energy relationship using the Hammett equation suggests a free radical mechanism. Activation parameters provided evidence for an associative transition step. The data obtained revealed a complex system of reactions. With the experimental results obtained in these studies, mechanisms for the iron(I) catalysed cross-coupling reaction were proposed. An X-ray absorbance spectroscopy study was conducted in iron complexes in order to illuminate the role of iron of the species. Reaction mixtures of typical cross-coupling reactions were examined at the end of the reaction in order to detect iron complexes and characterise them. A reaction time-dependent study was undertaken to determine the iron complexes in the reaction mixture. A kinetic study on the Negishi cross-coupling using iron(II) was conducted. The experimental results from the kinetic study on iron(I) and the kinetic study on iron(II) were used to propose a mechanism of reaction for the iron catalysed Negishi cross- coupling. The development of a new cross-coupling system using manganese as pre-catalyst was explored. The use of different ligands, additives and conditions of the reaction was tested. 2 Acknowledgements A massive thanks to my supervisor Professor Robin Bedford for giving the opportunity to work with him and for the help provided. I will always admire your enthusiasm and creativity. Thanks to all my friends in the Bedford group: Starting with Michelle, Paul, Johnny and Dom who introduced me to everything in the laboratory and to the life in the UK. Thanks to Sanita, Stephen, Harry, Mattia and Soneela for all the good chats, for enjoying my great taste in music and making a fun work environment in the lab. I thank the postdocs in the Bedford group: Antonis, David, Peter and Carolina, who were always helpful and taught me a lot. I appreciate the willingness to share your expertise. I thank all my friends in Bristol, particularly to the Mexican community in Bristol which gave a little piece of my country abroad. I am so grateful to my parents, who have always been rooting for me and cheering me up. A massive thanks to my brother, who is always someone I could talk without judgment. I am grateful to my grandfather, who helps me and cares about me. Thanks to the Consejo Nacional de Ciencia y Tecnología (CONACyT) for its financial support throughout my doctoral studies. 3 I declare that the work in this dissertation was carried out in accordance with the requirements of the University's Regulations and Code of Practice for Research Degree Programmes and that it has not been submitted for any other academic award. Except where indicated by specific reference in the text, the work is the candidate's own work. Work done in collaboration with, or with the assistance of, others, is indicated as such. Any views expressed in the dissertation are those of the author. SIGNED: ............................................................. DATE:.......................... 4 Abbreviations Ac Acetyl EPR Electron Paramagnetic Ots Tosylate Resonance acac Acetylacetonate PEG Polyethylene glycol eq Equivalents Ar Aryl Piv Pivalate EXAFS Extended X-ray B(Arf)4 Tetrakis[3,5- absorption fine structure PPh3 Triphenylphosphine bis(trifluoromethyl)phenyl]borate Py Pyridine Feact Active Iron Catalyst Bn Benzyl RE Reductive elimination Feoff Iron off-cycle species cat. Catalyst RT Room Temperature Feon Iron on-cycle species COD Cyclooctadiene s Seconds Feout Stable iron species Cy Tricyclohexylphosphine SALEN N,N'- Fepre Iron pre-catalyst DABCO 1,4- bis(salicylidene)ethylenediamine diazabicyclo[2.2.2]octane h Hour sBu Secbutyl dba Dibenzylideneacetone HMPA Hexamethylphosphorami SET Single electron transfer dbm Dibenzoylmethane de SET Single electron transfer depe Diethylenephosphine iBu isobutyl T Temperature DFT Density functional theory IMes 1,3-Dimesitylimidazol-2- tBu tertbutyl DIBAL ylidene, 1,3-bis(2,4,6- Diisobutylaluminum hydri trimethylphenyl)-imidazolium Tf Triflate de iPr Isopropyl TFA Trifluoroacetic acid DMA Dimethylacetamide M Metal THF Tetrahydrofuran DME Dimethoxyethane Mes Mesitylene TM Transition metal dpbz 1,2- min Minutes TMEDA N,N,N',N'- bis(diphenylphosphino)benzene tetramethylethylenediamine NHC N-heterocyclic dppe 1,2- TMS Tetramethylsilane bis(diphenylphosphino)ethane NMP N-Methyl-2-pyrrolidone XANES X-ray absorption near dppm NMR Nuclear Magnetic edge structure Bis(diphenylphosphino)m Resonance ethane XAS X-ray absorption OA Oxidative addition spectroscopy dppp 1,2- bis(diphenylphosphino)propane Otf Triflate 5 Table of contents Chapter 1 Introduction ................................................................................................................... 7 1.1 Metal-catalysed cross-coupling reactions ................................................................................. 8 1.2 First row transition metal catalysed cross-coupling reactions ................................................... 9 1.3 Palladium Cross-coupling reactions ........................................................................................ 11 1.4. Use of softer nucleophiles ..................................................................................................... 13 1.5 Iron as a catalyst .................................................................................................................... 23 Chapter 2. Exploring Fe(I) reactivity in Negishi Cross-Coupling ......................................................... 44 2.1 Introduction ........................................................................................................................... 45 2.2 General Considerations .......................................................................................................... 71 2.3 Preliminary UV-Vis studies in Fe catalysed cross-coupling. ..................................................... 72 2.4 Kinetic studies on the oxidation of Fe(I) ................................................................................. 76 2.5 Order of reaction ................................................................................................................... 88 2.6 Linear free energy relationship analysis using the Hammett equation. ................................... 97 2.7 Activation parameters of the reaction of [FeBr(dpbz)2] and BnBr in the presence of ZnBr2 ... 102 2.8 Mechanism of reaction. ....................................................................................................... 105 2.9 Conclusions and Future Work .............................................................................................. 109 Chapter 3. Further studies on the iron-catalysed cross-coupling .................................................... 111 3.1 Introduction ......................................................................................................................... 112 3.2 Results and discussion ......................................................................................................... 114 3.3 Monitoring the catalysis using FeBr2(dpbz)2 ......................................................................... 122 Chapter 4. Developing a novel Manganese-catalysed Negishi cross-coupling
Load more

Recommended publications
  • 23.5 Basicity and Acidity of Amines
    23_BRCLoudon_pgs5-0.qxd 12/8/08 1:22 PM Page 1122 1122 CHAPTER 23 • THE CHEMISTRY OF AMINES alkylamines, this resonance occurs at rather small chemical shift—typically around d 1. In aromatic amines, this resonance is at greater chemical shift, as in the second of the preceding examples. Like the OH protons of alcohols, phenols, and carboxylic acids, the NH protons of amines under most conditions undergo rapid exchange (Secs. 13.6 and 13.7D). For this reason, split- ting between the amine N H and adjacent C H groups is usually not observed. Thus, in the NMR spectrum of diethylamine,L the N H resonanceL is a singlet rather than the triplet ex- pected from splitting by the adjacent CHL2 protons. In some amine samples, the N H resonance is broadened and, like the OL H protonL of alcohols, it can be obliterated fromL the spectrum by exchange with D2O (the “DL2O shake,” p. 611). The characteristic 13C NMR absorptions of amines are those of the a-carbons—the carbons attached directly to the nitrogen. These absorptions occur in the d 30–50 chemical-shift range. As expected from the relative electronegativities of oxygen and nitrogen, these shifts are somewhat less than the a-carbon shifts of ethers. PROBLEMS 23.4 Identify the compound that has an M 1 ion at mÜz 136 in its CI mass spectrum, an IR 1 + = absorption at 3279 cm_ , and the following NMR spectrum: d 0.91 (1H, s), d 1.07 (3H, t, J 7Hz), d 2.60 (2H, q, J 7Hz), d 3.70 (2H, s), d 7.18 (5H, apparent s).
    [Show full text]
  • Comparative Strengths of Four Organic Bases in Benzene1 Marion Maclean Davis and Hannah B
    Journal of Research of the National Bureau of Standards Vol. 48, No. 5, May 1952 Research Paper 2326 Comparative Strengths of Four Organic Bases in Benzene1 Marion Maclean Davis and Hannah B. Hetzer Spectropho to metric studies have shown that the reaction of the base 1,3-di-o-tolylguani- dine with the acidic indicator dye bromophthalein magenta E (tetrabromophenolphthalein ethyl ester) in benzene at 25° C, like the reactions of 1,3-diphenylguanidine and 1,2,3-tri- phenylguanidine with the same indicator, can be represented by the following two equations: B + HA ^ BH+.A- (colorless base) (yellow acid) (magenta salt) BH+.A- + B^(BHB)+A- (blue salt) For ditolylguanidine, the equilibrium constants K\ and K2 for the first and second reactions, respectively, are estimated to be 1.1 X106 and 6.4. These values are compared with values for Ki and K2 previously found for di- and triphenylguanidine and the value of Ki found for triethylamine. The values for K\, which measure the relative tendencies of the bases to form salts with the indicator acid in benzene, would be expected to parallel the ionic dissociation constants of the bases in water. However, the parallelism is not good. Diphenylguanidine and ditolylguariidine, which are presumed to be weaker bases in water than triethylamine, are much more reactive in benzene. The results demonstrate how misleading the aqueous dissociation constants may be as a gage of the relative reactivities of bases in a nonaqueous solvent such as benzene. Steric and solvation effects are discussed. 1. Introduction i optical instruments then available, it was possible to make only roughly quantitative comparisons of Hantzsch and his coworkers were the first to J acidic strengths.
    [Show full text]
  • Chapter 16 the Chemistry of Benzene and Its Derivatives
    Instructor Supplemental Solutions to Problems © 2010 Roberts and Company Publishers Chapter 16 The Chemistry of Benzene and Its Derivatives Solutions to In-Text Problems 16.1 (b) o-Diethylbenzene or 1,2-diethylbenzene (d) 2,4-Dichlorophenol (f) Benzylbenzene or (phenylmethyl)benzene (also commonly called diphenylmethane) 16.2 (b) (d) (f) (h) 16.3 Add about 25 °C per carbon relative to toluene (110.6 C; see text p. 743): (b) propylbenzene: 161 °C (actual: 159 °C) 16.4 The aromatic compound has NMR absorptions with greater chemical shift in each case because of the ring current (Fig. 16.2, text p. 745). (b) The chemical shift of the benzene protons is at considerably greater chemical shift because benzene is aromatic and 1,4-cyclohexadiene is not. 16.6 (b) Among other features, the NMR spectrum of 1-bromo-4-ethylbenzene has a typical ethyl quartet and a typical para-substitution pattern for the ring protons, as shown in Fig. 16.3, text p. 747, whereas the spectrum of (2- bromoethyl)benzene should show a pair of triplets for the methylene protons and a complex pattern for the ring protons. If this isn’t enough to distinguish the two compounds, the integral of the ring protons relative to the integral of the remaining protons is different in the two compounds. 16.7 (b) The IR spectrum indicates the presence of an OH group, and the chemical shift of the broad NMR resonance (d 6.0) suggests that this could be a phenol. The splitting patterns of the d 1.17 and d 2.58 resonances show that the compound also contains an ethyl group, and the splitting pattern of the ring protons shows that the compound is a para-disubstituted benzene derivative.
    [Show full text]
  • British Chemical Abstracts
    BRITISH CHEMICAL ABSTRACTS A.-PURE CHEMISTRY JANUARY, 1935. General, Physical, and Inorganic Chemistry. Isotope effeet in the Lyman series of hydrogen. column current for a W cathode. For an oxido S. S. B a l l a r d and H. E. W h i t e (Physical Rev., cathode the p.d. depends on the no. of striations, but 1933, [ii], 43, 941).—Using H20 containing a high the results are not reproducible. M. S. B. [H2], six members of the Lyman series of H have Transition probabilities in the sharp and been observed as close doublets. In agrecment with. diffuse series of the alkalis. L. S. O r n s t e in and the theory of broadening of lines due to the Doppler J. K e y (Physiea, 1934,1, 945—952).—The transition effeet, the H1 component is broader than the H2. probability for p —d and s—p lines in Na and K L. S. T. has been determined using the a.c. arc. It has also Spin of hydrogen isotope. G. N. L e w is and been cale. for Rb and Cs from previous data. M. F. A s h l e y (Physical Rey., 1933, [ii], 43, 837).— M. S. B. The emission spectrum of mol. H , containing approx. Starting potential of the glow discharge in 25% HJ, 50% H XH2, and 25% Hi shows th at the neon-argon mixtures between large parallel spin of H2 is neither 0, 1/2, nor 3/2; it is, in all plates. I. Results.
    [Show full text]
  • John William Baker and the Origin of the Baker-Nathan Effect
    82 Bull. Hist. Chem., VOLUME 37, Number 2 (2012) JOHN WILLIAM BAKER AND THE ORIGIN OF THE BAKER-NATHAN EFFECT Martin D. Saltzman, Providence College, [email protected] The Baker-Nathan effect was a theory proposed by independent school in west London from 1909-1916. He John William Baker (1898-1967) and Wilfred Samuel was awarded a Royal Scholarship in Chemistry which Nathan (1910-1961) of Leeds University in 1935 to allowed him to enroll at the Imperial College of Science explain certain anomalous results obtained in SN2 reac- and Technology in London. His exceptional aptitude for tions carried out in solution. The explanation produced chemistry was shown by his passing the intermediate by them was expanded to a general type of no-bond exams for the B.Sc. Degree by the end of 1916. In April resonance known as hyperconjugation by Mulliken in 1917 he was conscripted and assigned to the Royal En- papers published in 1939 and 1941 (1). Hyperconjuga- gineers where he was commissioned a Lieutenant. His tion is today defined as the conjugation of polarized major responsibilities were in the area of water purifica- sigma bonds and adjacent pi orbitals. This theory has tion. In May 1918 he was sent to Mesopotamia (now Iraq) been applied to a host of anomalous physical measure- where he was assigned the same duties. He was finally ments such as bond lengths and dipole moments. The demobilized in 1920 and returned to Imperial where he Baker-Nathan effect as it was originally framed is no was awarded his B.Sc.
    [Show full text]
  • AND RESONANCE EFFECTS by Terence John Mireglia a Thesis
    Separation of inductive and resonance effects Item Type text; Thesis-Reproduction (electronic) Authors Miraglia, Terence John, 1939- Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 25/09/2021 12:11:08 Link to Item http://hdl.handle.net/10150/319551 s e p a r a t i o n o f i n d u c t i v e AND RESONANCE EFFECTS by Terence John Mireglia A Thesis Submitted to the Faculty of the DEPARTMENT OF CHEMISTRY In Partial Fulfillment of the Requirements For the Degree of MASTER o f s c i e n c e In the Graduate College THE UNIVERSITY OF ARIZONA 1 9 6 3 STATEMENT BY AUTHOR This thesis has been submitted in partial fulfill­ ment of requirements for an advanced degree at The Univer­ sity of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this thesis are allowable without special permission, provided that accurate acknowl­ edgment of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his judgment the proposed use of the material is in the interests of scholarship.
    [Show full text]
  • Proximity Effects. Kinetics, Mechanisms and Reactivity Correlations for the Acidic and Alkaline Hydrolysis of Ortho- Substituted-N-Methylbenzohydroxamic Acids
    Western Michigan University ScholarWorks at WMU Dissertations Graduate College 8-1977 Proximity Effects. Kinetics, Mechanisms and Reactivity Correlations for the Acidic and Alkaline Hydrolysis of Ortho- Substituted-N-Methylbenzohydroxamic Acids Irl E. Ward Western Michigan University Follow this and additional works at: https://scholarworks.wmich.edu/dissertations Part of the Organic Chemistry Commons Recommended Citation Ward, Irl E., "Proximity Effects. Kinetics, Mechanisms and Reactivity Correlations for the Acidic and Alkaline Hydrolysis of Ortho-Substituted-N-Methylbenzohydroxamic Acids" (1977). Dissertations. 2789. https://scholarworks.wmich.edu/dissertations/2789 This Dissertation-Open Access is brought to you for free and open access by the Graduate College at ScholarWorks at WMU. It has been accepted for inclusion in Dissertations by an authorized administrator of ScholarWorks at WMU. For more information, please contact [email protected]. PROXIMITY EFFECTS. KINETICS, MECHANISMS AND REACTIVITY CORRELATIONS FOR THE ACIDIC AND ALKALINE HYDROLYSIS OF o r t h q - substituted -n -methylbenzohydroxamic ACIDS by Irl E. Ward A Dissertation Submitted to the Faculty of the Graduate College in partial fulfillment of the Degree of Doctor of Philosophy Western Michigan University Kalamazoo, Michigan August 1977 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PROXIMITY EFFECTS. KINETICS, MECHANISMS AND REACTIVITY CORRELATIONS FOR THE ACIDIC AND ALKALINE HYDROLYSIS OF ORTHO-SUBSTITUTED-N-METHYLBENZOHYDROXAMIC
    [Show full text]
  • 16.5 Electrophilic Aromatic Substitution Reactions of Substituted Benzenes 763
    16_BRCLoudon_pgs4-3.qxd 11/26/08 9:07 AM Page 762 762 CHAPTER 16 • THE CHEMISTRY OF BENZENE AND ITS DERIVATIVES 16.19 Show two different Friedel–Crafts acylation reactions that can be used to prepare the follow- ing compound. ) CH O 3 S C CH3 ccL LL CH)3 16.20 The following compound reacts with AlCl3 followed by water to give a ketone A with the for- mula C10H10O. Give the structure of A and a curved-arrow mechanism for its formation. O S H3C CH2CH2 C Cl L L L L ELECTROPHILIC AROMATIC SUBSTITUTION REACTIONS 16.5 OF SUBSTITUTED BENZENES A. Directing Effects of Substituents When a monosubstituted benzene undergoes an electrophilic aromatic substitution reaction, three possible disubstitution products might be obtained. For example, nitration of bromoben- zene could in principle give ortho-,meta-, or para-bromonitrobenzene. If substitution were totally random, an ortho:meta:para product ratio of 2 : 2 :1 would be expected. (Why?) It is found experimentally that this substitution is not random, but is regioselective. Br Br Br Br " " NO2 " " HNO 3 M (16.27) acetic acid i i ++i i M NO2 bromobenzene o-bromonitrobenzene "NO2 m-bromonitrobenzene (36%) (2%) p-bromonitrobenzene (62%) Other electrophilic substitution reactions of bromobenzene also give mostly ortho and para isomers. If a substituted benzene undergoes further substitution mostly at the ortho and para positions, the original substituent is called an ortho, para-directing group. Thus, bromine is an ortho, para-directing group, because all electrophilic substitution reactions of bromoben- zene occur at the ortho and para positions.
    [Show full text]
  • [1978] Application of the Hammett Equation to Equilibrium Acidities.Pdf
    Substituted Acetophenones J. Org. Chem., Vol. 43, No. 9, 1978 1763 References and Notes (11) J. E. Leffler and E. Grunwald, “Rates and Equiliibria of Organic Reactions”, Wiley, New York, N.Y., 1963, p 224. (1) Contribution No. 244. (12) This was estimated from kobd = 4.1 X IOT3 s-l for 3a with 0.36 M KOH (2) (a) R. E. Parker and N S. Isaacs, Chem. Rev., 59, 737 (1959); (b) A. Ro. in 70% MeOH. That is, k8 = 4.1 X 10-3/(0.36 X 0.41 X (1/300)) = 8.3, sowski, “Heterocyclic Compounds with Three and Four-Membered Rings”, where 0.41 is a factor of undissociated 3a (cf. K, = 4 M-’) and 1/300 is Part I, A. Weissberger, Ed., Interscience, New York, N.Y.. 1964, Chapter the molar ratio of 5:3. 1. (13) Y. Sawaki and Y. Ogata, J. Am. Chem. SOC.,97, 6983 (1975). (3) (a) W. H. Richardson and R. S. Smith, J. Org. Chem., 33, 3882 (1968); (b) (14) Y. Ogata, Y. Sawaki, and M. Shiroyama, J. Org. Chem., 42, 4061 W. Adam and A. Rios, Chem. Commun., 822 (1971). (1977). (4)(a) M. R. Barusch and J. Q. Payne, J. Am. Chem. SOC.,75, 1987 (1953); (15) J. Murto, “The Chemistry of the Hydroxyl Group”, Part 2, S. Patai, Ed., In- (b) H. Kropf, M. Ball, H. Schroder. and G. Witte, Tetrahedron, 30, 2943 terscience, London, 1971, p 1087. (1974). (16) W. H. Richardson and R. S. Smith, J. Am. Chem. SOC.,91, 3610 (1969). (5) R.
    [Show full text]
  • Electrostatic and Stereoelectronic Effects in Carbohydrate Chemistry
    Momcilo Miljkovic Electrostatic and Stereoelectronic E ects in Carbohydrate Chemistry Electrostatic and Stereoelectronic Effects in Carbohydrate Chemistry Momcilo Miljkovic Electrostatic and Stereoelectronic Effects in Carbohydrate Chemistry Momcilo Miljkovic Pennsylvania State University Hershey, Pennsylvania, USA ISBN 978-1-4614-8267-3 ISBN 978-1-4614-8268-0 (eBook) DOI 10.1007/978-1-4614-8268-0 Springer New York Heidelberg Dordrecht London Library of Congress Control Number: 2013955044 © Springer Science+Business Media New York 2014 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. Exempted from this legal reservation are brief excerpts in connection with reviews or scholarly analysis or material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Duplication of this publication or parts thereof is permitted only under the provisions of the Copyright Law of the Publisher’s location, in its current version, and permission for use must always be obtained from Springer. Permissions for use may be obtained through RightsLink at the Copyright Clearance Center. Violations are liable to prosecution under the respective Copyright Law. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.
    [Show full text]
  • Glossary of Terms Used in Physical Organic Chemistry
    PUre & AppL. Chem,, Vol. 51, pp. 1725-1801. 0033-4545/79/0801-1725 $02.00/0 Pergamon Press Ltd. 1979. Printed in Great Britain. ©IUPAC PROVISIONAL INTERNATIONAL UNION OF PURE AND APPLIED CHEMISTRY ORGANIC CHEMISTRY DIVISION COMMISSION ON PHYSICAL ORGANIC CHEMISTRY* GLOSSARY OF TERMS USED IN PHYSICAL ORGANIC CHEMISTRY Compiled and Edited by VICTOR GOLD Comments on these proposals should be sent within 8 months of Publication to the S=etary of the Commission: Dr. J. R. PENTON Technisch-Chenmches Laboratorium der EidgenOssischen Technischen Hochschule Zürich Universitlltstrasse 6 CH-8092 Zürich, Switzerland Comments from the viewpoint of languages other than English are encouraged. These may have special significance regarding the eventual publication in various countries of translations of the nomenclature finally approved by IUPAC. *The mernbership of the Commission during the period in which this Glossary was prepared was as follows: J. F. DUNNETT (Titular Mernber, 1973-79; Chairman, 1978-; USA) A. R. H. COLE (Associate Member, 1974-79; Australia) V. GOLD (Titular Mernber, 1973·79; UK) R. D. GUTHRJE (Associate Mernber, 1977-81; USA) G.ILLUMINATI (Titular Mernber, 1977-81; ltaly) R. A. Y. JONES(AssociateMernber,l977-81; UK) J. MARCH(AssociateMernber,1977-81; USA) J. R. PENTON (Titular Mernber and Secretary, 1973·79; Switzerland) M. J. PERKINS (Titular Mernber, 1977-81; UK) J. REEDIJK (AssociateMernber,1977-81; Netherlands) C. RÜCHARDT (Titular Mernber, 1973-77; Federal Republic ofGermany) K. SCHWETLICK (Titular Mernber, 1977-81; German Dernocratic Republic) A. STREITWIESER(Titular Member, 1973-77; Associate Mernber, 1977-81; USA) J. TOUL!,l!C (TitularMernber,l973-79; France) H. ZOLLINGER (Titular Mernber, 1973-79; Chairman, 1973-78; Switzerland) CONTRIBUTORS TO THE GLOSSARY w.
    [Show full text]
  • Chapter 23 the Chemistry of Amines
    Instructor Supplemental Solutions to Problems © 2010 Roberts and Company Publishers Chapter 23 The Chemistry of Amines Solutions to In-Text Problems 23.1 (b) (d) (f) 23.2 (b) N,N-Dimethyl-p-nitroaniline (common), or 1-dimethylamino-4-nitrobenzene (c) Dicyclohexylamine (common), or N-cyclohexylcyclohexanamine 23.3 (b) Apply the principle used in part (a). The order of increasing carbon–nitrogen bond length is A < C < B Compound B has a true carbon–nitrogen single bond, and hence has the longest carbon–nitrogen bond. Compound A has a true carbon–nitrogen double bond, and hence has the shortest carbon–nitrogen bond. The carbon–nitrogen bond of C has some double-bond character because of resonance interaction of the nitrogen unshared pair with the double bond. (Draw the appropriate resonance structure.) Another way to compare the C—N bond lengths of compounds B and C is to note that the C—N bond in B is an sp3–sp3 single bond, whereas the C—N bond in C is an sp2–sp3 single bond, and to remember that s bonds with greater s character are shorter. (See discussion on text pp. 127 and 678.) 23.5 The NMR spectrum indicates the presence of only two phenyl hydrogens, and the singlet absorptions at d 2.07 and d 2.16 indicate the presence of chemically nonequivalent methyl groups in the ratio 2:1. Only compound (2), 2,4,6- trimethylaniline, fits the data. The two resonances at d 2.07 and d 2.16 correspond to the ortho and para methyl groups, respectively, and the d 3.19 resonance to the —NH2 protons of the amine.
    [Show full text]