Research Collection Doctoral Thesis Synthesis and investigation of highly functionalized derivatives of buckminsterfullerene Author(s): Haldimann, Richard F. Publication Date: 1998 Permanent Link: https://doi.org/10.3929/ethz-a-001984833 Rights / License: In Copyright - Non-Commercial Use Permitted This page was generated automatically upon download from the ETH Zurich Research Collection. For more information please consult the Terms of use. ETH Library Diss. ETH Nr. 12856 Synthesis and Investigation of Highly Functionalized Derivatives of BuckminsterfuIIerene A dissertation submitted to the SWISS FEDERAL INSTITUTE OF TECHNOLOGY ZURICH for the degree of Doctor of Natural Sciences Presented by Richard F. Haldimann dipl. Chem. ETH born July 6,1969 from Les Brenets, NE accepted on the recommendation of Prof. Dr. Francois Diederich, examiner Prof. Dr. Peter Chen, co-examiner Zurich 1998 To my parents, R.C. Haldimann and 'the true scientist' M.A. Haldimann, for their support, love and being true friends. Acknowledgements I would like to thank Professor Francois Diedench for his financial and intellectual support of the work described in this dissertation His visionary suggestions and contagious enthusiasm as well as the freedom in design and execution of the projects have made the past years a great learning experience A special thanks goes to Dr Lyle Isaacs who taught me all the intricate secrets of fullerene chemistry and who showed me how to do scientific research Christian Fokas, for his friendship and his great work during his Diplomarbeit Ernst-Udo Wallenborn I thank for his perseverance and his chemical and computational brilliance which were instrumental in the theoretical analysis of the reaction mechanism described m chapter 5 Dr Marcos G6mez L6pez, Phihpp Lustenberger and Dr Jeanne Crassous are thanked for proof-reading and providing many valuable suggestions which substantially improved the manuscript I thank Prof Dr M Saunders, A Khong, and Dr H Jimenez-Vdzquez for recording the 3He-spectra I am grateful to all the members of the ETH staff for the outstanding services they provided In particular I would like to thank Dr Walter Amrein, Rolf Hafliger, Hans Ulnch Hediger and Oswald Greter for measuring the mass spectra, Professor Bernhard Jaun, Bngitte Brandenberg, Dr Monika Sebova, Muriel Hemmi, and Phihpp Zumbrunnen for recording some of the NMR spectra I thank also Dr Carlo Thilgen for his help naming the fullerene compounds Markus Ruttimann, Robert Epple, Thomas Carell, and in the latter stages of my thesis, Dr Marcos G6mez-L6pez and Dr Marc Leduc made sure that working m the lab E39 a was often scientifically challenging but always fun experience I am particularly indebted to my mother, my sister Helene, Markus Ruttimann and his familly, Robert Epple, Lars Burgdorf, and Marc-Andr6 (Tonci) Haldunann and the family in the U S who stood by me in the darkest period of my life A special thanks goes to Gabriela Bischofberger for her support in some of the synthesis, for two wonderful years, and simply for being I also would like to thank Prof Dr Jack Dunitz for the often amusing sometimes confusing but always very insightful discussions on chemistry and life Finally, my heartfelt thanks goes to wonderful Andrea Szekeres for her patience, support and love Parts of this thesis have been published or are submitted for publication: • L. Isaacs R. F. Haldimann, F. Diederich, Angew. Chem. 1994, 706, 2434-2437; Angew. Chem. Int. Ed. Engl. 1994, 33, 2339-2342. Tether-Directed Remote Functionalization of Buckminsterfullerene. • R. F. Haldimann, F.-G. Klamer, F. Diederich, Chem. Commun. 1997, 237-238. Reactions of C2v-Symmetrical C60 Pentakis-Adducts with Diazomethane: Regioselective Formation of Hexakis- to Octakis-Adducts and Mechanism of Methanofullerene Formation by Addition of Diazomethane Followed by Dinitrogen Extrusion. • M. Riittimann, R. F. Haldimann, L. Isaacs, F. Diederich, A. Khong, H. Jimenez- VSzquez, R.J. Cross, M. Saunders, Chem. Eur. J. 1997,5, 1071-1076. nr-Electron Ring-Current Effects in Multiple Adducts of 3He@C60 and 3He@C7o: A 3He NMR Study. • L. Isaacs, F. Diederich, R. F. Haldimann, Helv. Chim. Acta 1997, 80, 317-342. Multiple Adducts of Cgo by Tether-Directed Remote Functionalization and Synthesis of Soluble Derivatives of New Carbon Allotropes C„(6o+5)- • F. Cardullo, P. Seiler, L. Isaacs, J.-F. Nierengarten, R. F. Haldimann, F. Diederich, Helv. Chim. Acta 1997, 80, 343-371. Bis- through Tetrakis-Adducts of C6o by Reversible Tether-Directed Remote Functionalization and Systematic Investigation of the Changes in Fullerene Properties as a Function of Degree, Pattern, and Nature of Functionalization. • E.-U. Wallenborn, R. F. Haldimann, F.-G. Klarner, F. Diederich, Chem. Eur. J. 1998, in press. Theoretical Investigation of the Origin of Regioselectivity on Methanofullerene Formation by Addition of Diazo Compounds: A Model Study Parts of this thesis were presented at international conferences. • R. F. Haldimann, F.-G. Klarner, F. Diederich, oral presentation held at the 1997 Joint International Meeting - The 192nd Meeting of The Electrochemical Society, Inc. and the 48th Annual Meeting of The International Society of Electrochemistry - "Fullerenes: Chemistry, Physics, and New Directions", Paris, 31. August - 5. September, 1997. Reactions of C2v-Symmetrical C60 Pentakis-Adducts with Diazomethane: Regioselective Formation of Hexakis- to Octakis-Adducts and Mechanism of Methanofullerene Formation by Addition of Diazomethane Followed by Dinitrogen Extrusion. • R. F. Haldimann, E.-U. Wallenborn, F.-G. Klarner, F. Diederich, poster presentation at the 36th IUPAC Congress, Genf, 17. - 22. August, 1997. Regioselective Formation of Hexakis- to Octakis-Adducts and Mechanism of Methanofullerene Formation by Addition of Diazomethane Followed by Dinitrogen Extrusion. Table of Contents Table of Contents Table of Contents i Abbreviations v Summary viii Zusammenfassung xi 1. Introduction to Buckminsterfullerene 1 1.1 The Discovery of the Fullerenes 2 1.2 Separation and Characterization of Cgo and the Higher Fullerenes 3 1.3 Purification of C60 4 1.4 Structural Aspects of the Fullerenes 6 1.4.1 The Isolated Pentagon Rule (IPR) 6 1.4.2 The Molecular Structure of C60 8 1.4.3 The Electronic Structure of C60 9 1.5 The Physical Properties of C60 12 1.5.1 The Heat of Formation 12 1.5.2 Solubility 13 1.5.3 The UV/VIS Spectrum of C6o 15 1.5.4 The Ring Currents and Magnetic Properties of Cat 17 1.5.5 The'3CNMR Spectrum of C6o 20 1.5.6 The IR Spectrum of C60 21 1.5.7 Photophysical Properties 21 2. The Principles of Reactivity of C60 24 2.1 General Considerations of the Reactivity of Ceo 24 2.2 Charge and Spin Densities in Nucleophilic and Radical Reactions of Buckminsterfullerene 25 2.2.1 Nucleophilic Additions Part 1: Charge Distribution 25 2.2.2 Radical Additions: Spin Localization 27 2.3 Establishing the Reactivity of C6o as an Electron Deficient Alkene by Metal Complexation 29 2.3.1 Nucleophilic Additions Part 2: The Bingel Reaction and Related Nucleophilic Cycloaddition Reactions of C6o 31 2.3.2 [4+2] Cycloadditions: Diels-Alder Reactions with C6o 33 2.3.3 [3+2] Cycloadditions: Additions of Diazo and Azide Derivatives 36 2.3.4 [2+1] Cycloadditions 43 Table of Contents 2 4 Multiple Functionahzation of Cgo 46 2 4 1 Nomenclature for Multiple Adducts of C^o 46 2 4 2 Octahedral Addition Patterns 47 2 4 2 1 Reversible Multiple Functionahzation with Stencally Demanding Addends 47 2 4 2 2 Irreversible Multiple Functionahzation with Stencally Demanding Addends 48 2 4 3 Selective Crystallization The Special Case of the trans-l Addition Pattern and aos-1 ,cis-l,cis-\ Tns-Adduct 53 2 4 4 6-5 Open and 6-6 Open Bis-Adducts 55 2 5 Multiple Radical Additions 60 3. Investigation of the Chemical Properties of Highly Functionalized Buckminsterfullerene 65 3 1 Tether-Directed Remote Functionahzation of Qo 65 3 1 1 Introduction 65 3 12 Application of the Tether-Directed Remote Functionahzation Methodology to a High Yield Synthesis of an e Bis-Adduct of C60 67 3 1 3 Extension of the Tether-Directed Remote Functionahzation of C6o from Tns- to Hexakis-Adducts 68 3 2 Investigation of the Chemical Properties of the C2V Symmetrical Pentakis-Adduct 90 71 3 2 1 Introduction 71 3 2 2 Exploiting the Confinement of the Reactivity of C2V Symmetrical Pentakis Adducts of C60 to a Single Double Bond Synthesis of Highly Functionalized Homofullerene Derivatives 73 3 2 2 1 Preliminary Remarks 73 3 2 2 2 Synthesis of a Cj-Symmetncal Monopyrazohno- Hexakis-Adduct of C60 73 3 2 2 3 Establishing the Regioselectivity of the Dinitiogen Extrusion of Highly Functionalized Fullerene-Pyrazohne Derivatives Parti Regiospecific Synthesis of a C\- Symmetrical Homofullerene Hexakis-Adduct of C^o via Thermal Dimtrogen Extrusion from a Pyrazohne Precursor 75 3 2 2 4 Establishing the Regioselectivity of the Dimtrogen Extrusion of Highly Functionalized Fullerene-Pyrazohne Derivatives Part 2 Photolysis of the Monopyrazohno-Hexakis Adduct of C6o 77 3 2 2 5 Regiospecific Synthesis of a Tns-Homofullerene Octakis-Adduct of Ceo 81 3 2 2 6 Regioselective Synthesis of a Bis-Homofullerene Heptakis Adduct of C60 84 3 2 2 7 Treatment of the Heptakis Adduct with Diazomethane The "Geminal"-Heptakis-Adduct is Not an Intermediate in the Formation of the Octakis adduct 86 3 2 2 8 Attempted Synthesis of a C2v-Symmetncal Tetrakis- Homofullerene Nonakis-Adduct of C^o 88 3 2 2 9 Attempted Oxidative Opening of the Fullerene Sphere 89 3 2 2 10 Synthesis of a Bis-Homofullerenediol Heptakis-Adduct of