DOCSLIB.ORG

SFU Thesis Template Files

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
SFU Thesis Template Files Synthetic Design and Development of Sterically-Protected Hydroxide-Conducting Polymers for Energy Conversion Devices by Andrew Gordon Wright B.Sc. (Hons), Simon Fraser University, 2012 Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in the Department of Chemistry Faculty of Science Andrew Gordon Wright 2016 SIMON FRASER UNIVERSITY Fall 2016 Approval Name: Andrew Gordon Wright Degree: Doctor of Philosophy (Chemistry) Title: Synthetic Design and Development of Sterically- Protected Hydroxide-Conducting Polymers for Energy Conversion Devices Chair: Dr. Roger G. Linington Associate Professor Examining Committee: Dr. Steven Holdcroft Senior Supervisor Professor Dr. Andrew J. Bennet Supervisor Professor Dr. Vance E. Williams Supervisor Associate Professor Dr. Robert A. Britton Internal Examiner Professor Dr. Patric Jannasch External Examiner Professor Department of Chemistry Lund University Date Defended/Approved: October 06, 2016 ii Abstract The production of renewable energy conversion devices is crucial in reducing greenhouse gas emissions and sustaining the energy required for future generations. However, most energy conversion devices currently available have high costs, which greatly slow down any transition from non-renewable combustion devices. The most promising low-cost, renewable energy conversion devices are based on anion- conducting membranes, such as those found in hydrogen fuel cells, water electrolyzers, redox flow batteries, and electrodialysis. Unfortunately, the current lifetime of such devices is too short for wide-spread adoption. The main issue is the instability of the alkaline anion exchange membrane towards caustic hydroxide. While a significant amount of research has been on demonstrating materials that have longer lifetimes, little work has been concentrated on investigating the degradation pathways on small molecule model compounds. By understanding the chemistry behind their weakness, materials can be specifically designed to counter such pathways. This then leads towards specifically designed polymers with high endurance. The development towards permanently-stable, alkaline anion exchange membranes is the focus of this thesis. Throughout this thesis, new model compounds are developed and extensively characterized. Using new stability tests, the degradation pathways are identified and the stability is quantitatively compared. Novel polymers are then prepared, which are designed to mimic the highest stability small molecule compounds. Steric hindrance is found to be the most promising method towards durable cationic polymers. From Chapter 2 to Chapter 5, the prepared materials become more and more resistant to hydroxide, demonstrating development in the correct direction. Keywords: alkaline anion exchange membrane; hydroxide-conducting polymer; steric hindrance; benzimidazolium; fuel cell; organic chemistry iii Dedication For Mom & Dad, whose love and support allow me to pursue my own dreams iv Acknowledgements I am grateful to Prof. Steven Holdcroft for allowing me to be a part of his lab over the years. Thanks to his guidance and advice and giving me the freedom to investigate new ideas, I have been able to accomplish more than I ever thought possible. His enthusiasm and optimism for science has always motivated me to do more research. I would also like to thank Prof. Andrew Bennet and Prof. Vance Williams for their constructive feedback and advice as supervisory committee members. I would like to thank present and previous Holdcroft Group members and co- authors for their suggestions and assistance during my research, especially Thomas Weissbach, Dr. Jiantao Fan, Benjamin Britton, Bryton Varju, Elizabeth Kitching, and Dr. Hsu•Feng Lee. I would specifically like to thank Mr. Owen Thomas and Dr. Tim Peckham for mentoring me when I started in this lab and helping me get onto the right track towards success. I would like to give a special thanks to the SFU Department of Chemistry faculty and staff that helped me along the way. Specifically, Dr. Andrew Lewis and Yilin Zhang for NMR assistance, Hongwen Chen for MS assistance, Bruce Harwood for glassware repair and modification, and Anthony Slater for electronics repair. I would also like to thank Prof. Daniel Leznoff and Dr. Jeffrey Ovens for training and assistance on single crystal XRD. Lastly, my mother, father, brother, and sister have always been there to support me throughout my life. Despite never being in the same place for more than eight years, they always made me feel at home. My lovely wife, Deena, helps me be better and get the most out of life. Without them, I would not be the man I am today. v Table of Contents Approval .......................................................................................................................... ii Abstract .......................................................................................................................... iii Dedication ...................................................................................................................... iv Acknowledgements ......................................................................................................... v Table of Contents ........................................................................................................... vi List of Tables .................................................................................................................. ix List of Figures.................................................................................................................. x List of Schemes ............................................................................................................. xv List of Acronyms ........................................................................................................... xvii Chapter 1. Introduction ............................................................................................. 1 1.1. Energy Conversion Devices.................................................................................... 2 1.2. Anion Exchange Membranes .................................................................................. 5 1.3. Poly(benzimidazole) ............................................................................................. 10 1.4. Thesis Overview ................................................................................................... 16 Chapter 2. Water-Insoluble and Hydroxide-Stable Ionenes .................................. 18 2.1. Introduction ........................................................................................................... 18 2.2. Experimental ........................................................................................................ 20 2.2.1. Materials .................................................................................................. 20 2.2.2. Synthesis ................................................................................................. 20 2.2.3. Membrane Preparation ............................................................................ 29 2.2.4. Degree of Methylation.............................................................................. 29 2.2.5. Ion-Exchange Capacity ............................................................................ 30 2.2.6. Ion-Exchange Procedure ......................................................................... 30 2.2.7. Electrochemical Impedance Spectroscopy .............................................. 30 2.2.8. Water Uptake (Wu) ................................................................................... 31 2.2.9. Degradation Procedure ............................................................................ 31 2.2.10. Deuterium-Exchange Experiment ............................................................ 32 2.2.11. Variable Temperature 1H NMR Spectroscopy .......................................... 32 2.3. Results and Discussion ........................................................................................ 33 2.3.1. Synthesis ................................................................................................. 33 2.3.2. Ionic Conductivity and Water Uptake ....................................................... 37 2.3.3. Hydroxide Stability ................................................................................... 39 2.3.4. Atropisomerization ................................................................................... 43 2.4. Conclusion ............................................................................................................ 45 Chapter 3. Studying HMT-PMBI on Larger Scales ................................................. 46 3.1. Introduction ........................................................................................................... 46 3.2. Experimental ........................................................................................................ 48 3.2.1. Materials .................................................................................................. 48 3.2.2. Synthesis ................................................................................................. 49 3.2.3. Membrane Preparation ............................................................................ 54 vi 3.2.4. Degree of Methylation Determination ....................................................... 55 3.2.5. Ion-Exchange Capacity (IEC) .................................................................
Load more

Recommended publications
  • Studies on Nucleoside H-Phosphonoselenoate Chemistry and Chalcogen Exchange Reaction Between P(V) and P(III) Compounds
    Studies on nucleoside H-phosphonoselenoate chemistry and chalcogen exchange reaction between P(V) and P(III) compounds Martin Kullberg Stockholm University 2005 Doctoral Dissertation Department of Organic Chemistry Arrhenius Laboratory Stockholm University ISBN 91-7155-163-8 Abstract In this thesis, the chemistry of compounds containing P-Se bonds has been studied. As a new addition to this class of compounds, H-phosphonoselenoate monoesters, have been introduced and two synthetic pathways for their preparation have been developed. The reactivity of H-phosphonoselenoate monoesters towards a variety of condensing agents has been studied. From these, efficient conditions for the synthesis of H-phosphonoselenoate diesters have been developed. The produced diesters have subsequently been used in oxidative transformations, which gave access to the corresponding P(V) compounds, e.g. dinucleoside phosphoroselenoates or dinucleoside phosphoroselenothioates. Furthermore, a new selenizing agent, triphenyl phosphoroselenoate, has been developed for selenization of P(III) compounds. This reagent has high solubility in organic solvents and was found to convert phosphite triesters and H-phosphonate diesters efficiently into the corresponding phosphoroselenoate derivatives. The selenization of P(III) compounds with triphenyl phosphoroselenoate proceeds through a selenium transfer reaction. A computational study was performed to gain insight into a mechanism for this reaction. The results indicate that the transfer of selenium or sulfur from P(V) to P(III) compounds proceeds most likely via an X-philic attack of the P(III) nucleophile on the chalcogen of the P(V) species. For the transfer of oxygen, the reaction may also proceed via an edge attack on the P=O bond. Martin Kullberg 2005 Papers are reprinted with permission of the publishers I Table of contents List of Papers III Abbreviations IV 1.
    [Show full text]
  • Triphenyl Phosphite (TPP) EC No 202-908-4 CAS No 101-02-0
    Substance Evaluation Conclusion document EC No 202-908-4 SUBSTANCE EVALUATION CONCLUSION as required by REACH Article 48 and EVALUATION REPORT for Triphenyl Phosphite (TPP) EC No 202-908-4 CAS No 101-02-0 Evaluating Member State(s): UK Dated: March 2019 UK CA Page 1 of 101 March 2019 Substance Evaluation Conclusion document EC No 202-908-4 Evaluating Member State Competent Authority UK REACH CA Health and Safety Executive Redgrave Court Merton Road Bootle Merseyside L20 7HS Email:[email protected] Chemicals Assessment Unit Environment Agency Red Kite House, Howbery Park Wallingford Oxfordshire, OX10 8BD Email: [email protected] Year of evaluation in CoRAP: 2013 Before concluding the substance evaluation a Decision to request further information was issued on: 2 December 2015 Further information on registered substances here: http://echa.europa.eu/web/guest/information-on-chemicals/registered-substances UK CA Page 2 of 101 March 2019 Substance Evaluation Conclusion document EC No 202-908-4 DISCLAIMER This document has been prepared by the evaluating Member State as a part of the substance evaluation process under the REACH Regulation (EC) No 1907/2006. The information and views set out in this document are those of the author and do not necessarily reflect the position or opinion of the European Chemicals Agency or other Member States. The Agency does not guarantee the accuracy of the information included in the document. Neither the Agency nor the evaluating Member State nor any person acting on either of their behalves may be held liable for the use which may be made of the information contained therein.
    [Show full text]
  • Coordination Chemistry in Liquid Ammonia and Phosphorous Donor Solvents
    Coordination Chemistry in Liquid Ammonia and Phosphorous Donor Solvents Kersti B. Nilsson Faculty of Natural Resources and Agricultural Sciences Department of Chemistry Uppsala Doctoral thesis Swedish University of Agricultural Sciences Uppsala 2005 Acta Universitatis Agriculturae Sueciae 2005: number 21 ISSN 1652-6880 ISBN 91-576-7020-x © 2005 Kersti B. Nilsson, Uppsala Tryck: SLU Service/Repro, Uppsala 2005 Abstract Nilsson, K. B., Coordination chemistry in liquid ammonia and phosphorous donor solvents. Doctor’s dissertation. ISSN 1652-6880, ISBN 91-576-7020-x The thesis summarizes and discusses the results from coordination chemistry studies of solvated d10 metal and copper(II) ions, and mercury(II) halide complexes in the strong electron-pair donor solvents liquid and aqueous ammonia, trialkyl phosphite, triphenyl phosphite and trialkylphosphine. The main techniques used are EXAFS, metal NMR and vibrational spectroscopy, and crystallography. Four crystal structures containing ammonia solvated metal ions have been determined. Questions addressed concern whether any changes in the preferential coordination numbers and geometries occur when these metal ions are transferred from aqueous ammonia to liquid ammonia solution, or to phosphorous donor solvents. Liquid ammonia and trialkyl phosphites are found to possess similar electron-pair donor properties, DS=56 for both, while trialkylphosphines are known to be even stronger electron-pair donors. The studies reveal that the ammonia-solvated d10 metal ions obtain very different configurations in liquid ammonia, with gold(I) being linear, copper(I) and silver(I) trigonal, zinc(II) and mercury(II) tetrahedral, and cadmium(II), indium(III) and thallium(III) octahedral. The ammonia-solvated copper(I) and silver(I) ions are linear in aqueous ammonia solution because of the lower ammonia activity, as the third ammine complexes are very weak in aqueous systems.
    [Show full text]
  • Diaryl Alkylphosphonates and Methods for Preparing
    (19) TZZ_Z_T (11) EP 1 940 855 B1 (12) EUROPEAN PATENT SPECIFICATION (45) Date of publication and mention (51) Int Cl.: of the grant of the patent: C07F 9/12 (2006.01) C07F 9/145 (2006.01) 01.07.2015 Bulletin 2015/27 C07F 9/40 (2006.01) (21) Application number: 06849055.6 (86) International application number: PCT/US2006/060035 (22) Date of filing: 17.10.2006 (87) International publication number: WO 2007/079272 (12.07.2007 Gazette 2007/28) (54) DIARYL ALKYLPHOSPHONATES AND METHODS FOR PREPARING SAME DIARYL-ALKYLPHOSPHONATE UND HERSTELLUNGSVERFAHREN DAFÜR ALKYLPHOSPHONATES DE DIARYLE ET LEURS MÉTHODES DE SYNTHÈSE (84) Designated Contracting States: • YAO ET AL: "A concise method for the synthesis AT BE BG CH CY CZ DE DK EE ES FI FR GB GR of diaryl aryl- or alkylphosphonates" HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI TETRAHEDRON LETT., vol. 47, 22 November SK TR 2005 (2005-11-22), pages 277-281, XP002495388 Designated Extension States: • DATABASECA [Online] CHEMICAL ABSTRACTS AL BA HR MK RS SERVICE, COLUMBUS, OHIO, US HUDSON, HARRY R. ET AL: ’Quasiphosphonium (30) Priority: 18.10.2005 US 727619 P intermediates. I. Preparation, structure, and 18.10.2005 US 727680 P nuclear magnetic resonance spectroscopy of triphenyl and trineopentyl phosphite- alkyl halide (43) Date of publication of application: adducts’ Retrieved from STN Database 09.07.2008 Bulletin 2008/28 accession no. 1974:449742 & JOURNAL OF THE CHEMICAL SOCIETY, PERKIN TRANSACTIONS (60) Divisional application: 1: ORGANIC AND BIO-ORGANIC CHEMISTRY 11169075.6 / 2 395 011 (1972-1999) , (9), 982-5 CODEN: JCPRB4; ISSN: 0300-922X, 1974, (73) Proprietor: FRX Polymers, Inc.
    [Show full text]
  • Iodination of Poly(Ethylene Glycol) by a Mixture of Triphenyl Phosphite and Iodomethane
    CHEMIJA. 2008. Vol. 19. No. 2. P. 43–49 © Lietuvos mokslų akademija, 2008 © Lietuvos mokslų akademijos leidykla, 2008 Iodination of poly(ethylene glycol) by a mixture of triphenyl phosphite and iodomethane Ūla Bernadišiūtė*, Iodination of poly(ethylene glycol) (PEG) with the molecular weight 2000 and its monomethyl ether (MPEG) by the iodinating mixture of triphenyl phosphite and iodomethane was studied Tomas Antanėlis, in detail. The structure of the synthesized PEG (MPEG) iodides was confirmed by elemental analysis, FT-IR and 1H NMR spectroscopy. The degree of iodination (DI) of PEG (MPEG) was Aušvydas Vareikis, determined by two independent methods based on argentometric titration and 1H NMR spec- tra. Argentometric titration the (Mohr method) was found to be limited by the incomplete hy- Ričardas Makuška drolysis of PEG (MPEG) iodides, while the analysis based on 1H NMR spectroscopy became accurate at a high DI only. The highest DI of PEG (MPEG) was reached carrying out the reaction Department of Polymer Chemistry, of iodination in a hermetic reactor at 120 °C for 5 hours and using a double-fold excess of the Vilnius University, iodinating mixture. The synthesized PEG (MPEG) iodides with DI 90–95 mol% could be useful Naugarduko 24, for “grafting to” or even for polycondensation with diamines. LT-03225 Vilnius, Lithuania Key words: poly(ethylene glycol), iodination, PEG, Mohr method, PEGylation INTRODUCTION under solvent-free conditions using microwave irradiation was found to be a simple and highly chemoselective process [26]. Halogen-containing compounds are useful intermediates in or- A relatively simple method for iodination of alcohols was ganic synthesis [1, 2].
    [Show full text]
  • Measuring the Electronic Effect of Some Phosphines and Phosphites
    Measuring the electronic effect of some phosphines and phosphites By Sanaa Moftah Ali Abushhewa A dissertation submitted to the University of Manchester for the degree of Master of Science by research in the Faculty of Engineering and Physical Sciences. School of Chemistry 2010 Contents page Abstract 6 Declaration 7 Acknowledgement 8 1. Introduction 9 1.1 History of Phosphorus 9 1.2 Phosphorus (III) compounds 10 1.3 Preparation and Properties of Phosphines 11 1.4 Preparation and Properties of Phosphites 12 1.5 Bonding of phosphorus (III) ligands 14 1.6 Measurement of Electronic and Steric Effects 15 1.7 Steric parameter 17 1.8 Electronic parameter 17 1.9 Effects of electronegative substituents 21 1.10 Phosphines and Phosphites ligand effects 21 2. Experimental section 24 General conditions 25 2.1- Preparation of phosphites 25 2.1.1- Synthesis of 2, 2’- Biphenyl Chlorophosphite 25 2.1.2- Synthesis of 1H,1H,2H,2H-perfluorodecyldiphenyl phosphinite 25 2 2.1.3- Synthesis of 3-fluorophenyldiphenyl phosphinite 26 2.1.4- Synthesis of 2-fluorophenyldiphenyl phosphinite 26 2.1.5- Synthesis of 2, 2-biphenyltrifluoroethyl phosphinite 27 2.1.6- Synthesis of 2, 2'-biphenylhexafluoroisopropyl phosphinite 27 2.1.7-Synthesis of 2, 2'-biphenylpropyl phosphite 28 2.2-Preparation of P(III) Selenides 28 2.2.1- Synthesis of triphenylphosphine selenide 28 2.2.2- Synthesis of triphenylphosphite selenide 29 2.2.3- Synthesis of tris(2,4,6-trimethylphenyl)phosphite selenide 29 2.2.4- Synthesis of diphenyl(o-tolyl) phosphine selenide 30 2.2.5- Synthesis of 2, 2’-biphenyl
    [Show full text]
  • United States CC Patented May 16, 1961
    2,984,680 United States CC Patented May 16, 1961 2 similar to Example 1, supra, by placing 5.5 grams of phosphorous acid and 47.2 grams of tri(para-cresyl) 2,984,680 phosphite in the reaction ?ask. The phosphorous acid was again insoluble but began to go into solution after 13 METHOD FOR PREPARING DIPI-ENYL minutes of heating when the temperature reached 60° C. PHOSPHITES Heating was continued to a temperature of 100° C. Edward N. Walsh, Chicago Heights, 111., assignor to after 38 minutes. The product was cooled to give a ‘ Victor Chemical Works, a corporation of Illinois clear oil, n25D>=1.5469. 10 grams of this product was distilled in a molecular still at 115-125° C. at 5 microns N0 Drawing. Filed Apr. 30, 1956, Ser. No. 581,357 10 to yield 9.9 g. of di(para-cresyl) phosphite, n25D=1.5466, 8 Claims. (Cl. 260-461) which analyzed 11.7% P, Cl- nil (theory 11.8% P, 0.0% Cl), and had a speci?c gravity of 1.5669 ?g25 This invention relates to a method for making diaryl 15 phosphites and the products produced thereby. Example 3 More speci?cally, this invention relates to a novel, sim ple method whereby diaryl phosphites may be made by The process of Example 2, supra, was repeated using reacting a triaryl phosphite with phosphorous acid. 70.4 g. of tri(meta-cresyl) phosphite and 8.2 g. of phos Diaryl phosphites have been known since diphenyl 20 phorous acid. The acid went into solution at 65—68° phosphite was reported by Milobendzki and Szulgin, C.
    [Show full text]
  • Chemical Hazard Reviews Volume 2: Furniture Flame Retardancy Partnership
    Volume 2 Chemical Hazard Reviews Furniture Flame Retardancy Partnership: Environmental Profiles of Chemical Flame-Retardant Alternatives for Low-Density Polyurethane Foam September 2005 TABLE OF CONTENTS Page Introduction .................................................................. i Flame Retardant Alternatives: Triphenyl Phosphate ................................ 1-1 Flame Retardant Alternatives: Tribromoneopentyl Alcohol .......................... 2-1 Flame Retardant Alternatives: Tris(1,3-dichloro-2-propyl) Phosphate .................. 3-1 Flame Retardant Alternatives: Proprietary A: Chloroalkyl phosphate (1) ................ 4-1 Flame Retardant Alternatives: Proprietary B: Aryl phosphate ......................... 5-1 Flame Retardant Alternatives: Proprietary C: Chloroalkyl phosphate (2) ................ 6-1 Flame Retardant Alternatives: Proprietary D: Reactive brominated flame retardant ........ 7-1 Flame Retardant Alternatives: Proprietary E: Tetrabromophthalate diol diester ........... 8-1 Flame Retardant Alternatives: Proprietary F: Halogenated aryl ester ................... 9-1 Flame Retardant Alternatives: Proprietary G: Triaryl phosphate, isopropylated .......... 10-1 Flame Retardant Alternatives: Proprietary H: Halogenated aryl ester .................. 11-1 Flame Retardant Alternatives: Proprietary I: Organic phosphate ester ................. 12 -1 Flame Retardant Alternatives: Proprietary J: Aryl phosphate ........................ 13 -1 Flame Retardant Alternatives: Proprietary K: Aryl phosphate .......................
    [Show full text]
  • For the Proposed Expansion Project by Capacity Enhancement and Addition
    FOR THE PROPOSED EXPANSION PROJECT BY CAPACITY ENHANCEMENT AND ADDITION OF NEW PRODUCTS FOR MANURACTURING OF Tri phenyl phosphite @300 MT/Month, Poly phosphoric acid @30 MT/Month, Plastic Additives (Organic Phosphite) @240 MT/Month Organic Phosphates @50 MT/Month and addition of Styrenated Phenol @100 MT/Month Under Activity: 5(f), Category- B (Synthetic Organic Chemicals Industry) OF Located at: Plot No. 313/1, 40 Shed Area, GIDC Estate, Vapi-396 195, Dist- Valsad (Gujarat). PROJECT PRE-FEASIBILITY REPORT INDEX 1. Executive Summary……………………………………………………………………………………….………… 4 2. Introduction……………………………………………………………………………………..………….…………… 6 i. Identification of the Project and Proponent. 6 ii. Brief Description of the project 7 iii. Need of the project and its importance to the country and or region 10 iv. Demand –Supply Gap 10 v. Imports vs. Indigenous production 10 vi. Export Possibility / Domestic / export Markets 10 vii. Employment Generation (Direct and Indirect) due to the project. 10 3. Project Description…………………………………………………………………………………………………… 11 i. Type of Project including interlinked and interdependent projects, If any 11 ii. Location (map showing general location, Specific location, and project 13 boundary & project site layout)with coordinates iii. Profile of Project site 14 iv. Site Layout Plan 15 v. Details of alternate sites considered and the basis of selecting the proposed 16 site, particularly the environmental considerations gone into should be highlighted vi. Size or magnitude of operation 16 vii. Project description with process details (a schematic diagram/ flow chart 16 showing the project layout components of the project etc. should be given) viii. Resource optimization/ recycling and reuse envisaged in the project, If any, 29 should briefly outlined ix.
    [Show full text]
  • United States Patent Office Patented Sept
    3,403,186 United States Patent Office Patented Sept. 24, 1968 2 sible paths. For instance, phosphoric acid (U.S. 2,752,- 3,403,186 398) inhibits a discoloration of a phenol which is acceler STABILIZATION OF PHENOLS ated by contact with metal (steel containers, ducts, valves, Hans L. Schlichting, Grand Island, and Ellis I. Lichtblau, and so forth). But as known and illustrated later, the Kenmore, N.Y., assignors to Hooker Chemical Corpo 5 stabilization is less effective if the phenol is also exposed ration, Niagara Falls, N.Y., a corporation of New York to air and/or sunlight and/or additional trace amounts No Drawing. Filed Nov. 30, 1965, Ser. No. 510,683 of caustic or acids, such as hydrochloric acid, sulfuric 14 Claims. (CI. 260-621) acid, and so forth. Other stabilizers, for instance organic polybasic carboxylic acids (U.S. 2,672,485), or Schiff's bases (British 787,859) or amino acids (British 807,736) ABSTRACT OF THE DISCLOSURE 10 may inhibit more or less effectively a discoloration of a A mixture of a trivalent phosphorus-containing organic phenol which is promoted and accelerated by exposure to compound of the formula air and/or sunlight and/or additional trace amounts of Z. acids or alkalies. But the stabilization is less effective 5 (almost nil) if the phenol is also exposed to metal and/or P2 metal oxides, as for instance steel, iron, rust, and so Zer forth. where Z can be hydroxyl, Z and Z' can be hydrogen and It has now been found that a mixture of an aromatic Z, Z and Z' are selected from the group consisting of o-hydroxycarboxylic
    [Show full text]
  • Some New Observations on an Old Reaction: Disproportionation and The
    Issue in Honor of Prof. Cheng-Ye Yuan ARKIVOC 2004 (ix) 19-33 Some new observations on an old reaction: disproportionation and the formation of P-O-P intermediates in the Michaelis-Arbuzov reaction of triaryl phosphites with alkyl halides Harry R. Hudson* and Lubomira Powroznyk London Metropolitan University, 116-220 Holloway Road, London, N7 8DB, UK E-mail: [email protected] Dedicated to Professor Chengye Yuan on the occasion of his 80th birthday and in recognition of his distinguished contributions to organophosphorus chemistry (received 23 Feb 04; accepted 19 May 04; published on the web 21 May 04) Abstract Thermolysis of methyltriaryloxyphosphonium halides (ArO)3PMeX (X = Br or I) in the molten state (> 175 oC) was accompanied by disproportionation, with the formation of structures of the general type (ArO)nPMe4-nX (X = Br or I; n = 0-4). Further decomposition to give the corresponding aryl halides and phosphoryl derivatives became progressively slower as aryloxy groups were replaced by methyl. Thermal decomposition in CDCl3 (sealed tube) additionally confirmed the formation of novel species containing a P-O-P linkage. Products were identified by a combination of 31P and 1H NMR spectroscopy. Possible reaction mechanisms are discussed. Keywords: Michaelis-Arbuzov, quasiphosphonium, disproportionation, NMR spectroscopy Introduction The Michaelis-Arbuzov reaction is one of the best known and most fundamental reactions of organophosphorus chemistry encompassing, in its widest aspects, all reactions of phosphorus (III) esters with electrophilic reagents. The reaction proceeds via an alkoxy- or aryloxy- phosphonium intermediate 1, leading to the formation of a tetrahedral P(V) product containing a P=O bond (Scheme 1).1 δ+ δ− + − RO P: X Y RO P X Y O P X + RY 1 Scheme 1 ISSN 1424-6376 Page 19 ©ARKAT USA, Inc Issue in Honor of Prof.
    [Show full text]
  • This PDF Was Created from the British Library's Microfilm Copy of the Original Thesis. As Such the Images Are Greyscale and No
    IMAGING SERVICES NORTH Boston Spa, Wetherby West Yorkshire, LS23 7BQ www.bl.uk This PDF was created from the British Library’s microfilm copy of the original thesis. As such the images are greyscale and no colour was captured. Due to the scanning process, an area greater than the page area is recorded and extraneous details can be captured. This is the best available copy D67043ÌB6 \ l ì \ Attention is drawn to ^ the fact that the È copyright o f this thesis rests with its author. This copy o f the thesis has been supplied on condition that anyone who consults it is p- understood to recognise that its copyright rests with its author and that no quotation from the thesis''and no information derived from it may be published without the author’s .pri^^ written consent. - if r>r»FN,..ii Iimm f -pm ' r/. ' Hi. REPRODUCED FROM THE AVAILABLE COPY NEW ASPECTS OF THE MICHAELIS-ARBUZOV AND PERKOW REACTIONS A Thesis SubniittGd. Top the Degpee of* DOCTOR OP PHILOSOPHY of the COUNCIL FOR NATIONAL ACADEMIC AWARDS by Mrs Lubomyra POWROZNYK MSc (Lublin) THE POLYTECHNIC OP NORTH LONDON Holloway Road, London, N? 8 DB October 1985 ACKNOWLEDGEMENTS The authoress owes a great debt and wishes to express her deep gratitude to her supervisor. Dr, H, R. HUDSON, for liis constant guidance, kind patience and helpful discussions during this long investigation. Thanks are also extended to Dr. R. w. Matthews and Mr, J. Crowder for assistance with F and C n.m.r. measurements, and Dr. K. Henrick for X>ray diffraction studies.
    [Show full text]