Endohedral Metallofullerenes – Fullerenes with Metal Inside

Hisanori Shinohara Department of Chemistry, Nagoya University, Japan Nikos Tagmatarchis Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, Greece Foreword by Sir Harold Kroto

Foreword ix Preface xi Personal Reflection Nori Shinohara xiii 1 Introduction 1 1.1 The First Experimental Evidence of Metallofullerenes 1 1.2 Early Years of Metallofullerene Research 3 1.3 Conventional and IUPAC Nomenclature for Metallofullerenes 5 References 6 2 Synthesis, Extraction, and Purification 9 2.1 Synthesis of Endohedral Metallofullerenes 9 2.2 Solvent Extraction of Metallofullerenes from Primary Soot 14 2.3 Purification and Isolation by HPLC 15 2.4 Fast Separation and Purification with Lewis Acids 18 References 19 3 Molecular and Crystal Structures 23 3.1 Endohedral or Exohedral? A Big Controversy 23 3.2 Structural Analyses 25 References 37 4 Electronic States and Structures 43 4.1 Electron Transfer in Metallofullerenes 43 4.2 ESR Evidence on the Existence of Structural Isomers 45 4.3 Electrochemistry of Metallofullerenes 48 4.4 Similarity in the UV?]Vis?]NIR Absorption Spectra 51 4.5 Fermi Levels and the Electronic Structures 57 4.6 Metal Cage Vibration within Metallofullerenes 59 References 63 5 Carbide and Nitride Metallofullerenes 69 5.1 Discovery of Carbide Metallofullerenes 69 5.2 Fullerene Quantum Gyroscope: An Ideal Molecular Rotor 75 5.3 Nitride Metallofullerenes 77 References 81 6 Non?]Isolated Pentagon Rule Metallofullerenes 85 6.1 Isolated Pentagon Rule 85 6.2 Non?]IPR Metallofullerenes 86 References 89 7 Oxide and Sulfide Metallofullerenes 91 7.1 O xide Metallofullerenes 91 7.2 Sulfide Metallofullerenes 95 References 100 8 Non?]metal Endohedral Fullerenes 103 8.1 Nitrogen?]Containing N@C60 103 8.2 Phosphorus?]Containing P@C60 111 8.3 Inert Gas Endohedral Fullerenes He@C60, Ne@C60, Ar@C60, Kr@C60, and Xe@C60 112 8.4 Hydrogen?]Containing H2@C60 120 8.5 Water?]Containing H2O@C60 125 References 128 9 Scanning Tunneling Microscopy Studies of Metallofullerenes 133 9.1 STM Studies of Metallofullerenes on Clean Surfaces 133 9.2 Metallofullerenes as Superatom 135 9.3 STM/STS Studies on Metallofullerene Layers 137 9.4 STM/STS Studies on a Single Metallofullerene Molecule 139 References 141 10 Magnetic Properties of Metallofullerenes 145 10.1 Magnetism of Mono?]metallofullerenes 145 10.2 SXAS and SXMCD Studies of Metallofullerenes 149 References 154 11 Organic Chemistry of Metallofullerenes 157 11.1 Cycloaddition Reactions 157 11.2 Radical Addition Reactions 178 11.3 Miscellaneous Reactions 180 11.4 Donor Acceptor Dyads 185 11.5 Bis?]adduct Formation 194 11.6 Supramolecular Functionalization 195 11.7 Purification of Metallofullerenes by Chemical Methods 198 References 200 12 Applications with Metallofullerenes 209 12.1 Solar Cells 209 12.2 Biomedical Aspects of Water?]Soluble Metallofullerenes 221 References 226 13 Growth Mechanism 229 13.1 Carbon Clusters: A Road to Fullerene Growth 229 13.2 Roles Played by Metal Atoms in the Fullerene Growth 233 13.3 Top?]Down or Bottom?]Up Growth? 237 References 251 14 M@C60: A Big Mystery and a Big Challenge 255 14.1 What Happens to M@C60? 255 14.2 A Big Challenge: Superconductive Metallofullerenes 259 14.3 Future Prospects 261 References 262 Index 265