DOCSLIB.ORG

Discrete Fulleride Anions and Fullerenium Cations

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Discrete Fulleride Anions and Fullerenium Cations Chem. Rev. 2000, 100, 1075−1120 1075 Discrete Fulleride Anions and Fullerenium Cations Christopher A. Reed* and Robert D. Bolskar Department of Chemistry, University of CaliforniasRiverside, Riverside, California 92521-0403 Received June 22, 1999 Contents iii. Anisotropy 1100 iv. Problem of the Sharp Signals 1101 I. Introduction, Scope, and Nomenclature 1075 v. Origins of Sharp Signals 1102 II. Electrochemistry 1078 vi. The C O Impurity Postulate 1103 A. Reductive Voltammetry 1078 120 vii. The Dimer Postulate 1104 B. Oxidative Voltammetry 1079 2- C. Features of the C60 EPR Spectrum 1106 III. Synthesis 1079 3- D. Features of the C60 EPR Spectrum 1107 A. Chemical Reduction of Fullerenes to 1079 4- 5- Fullerides E. Features of C60 and C60 EPR Spectra 1107 i. Metals as Reducing Agents 1080 F. EPR Spectra of Higher Fullerides 1107 ii. Coordination and Organometallic 1080 G. EPR Spectra of Fullerenium Cations 1108 Compounds as Reducing Agents X. Chemical Reactivity 1108 iii. Organic/Other Reducing Agents 1081 A. Introduction 1108 B. Electrosynthesis of Fullerides 1081 B. Fulleride Basicity 1109 C. Chemical Oxidation of Fullerenes to 1081 C. Fulleride Nucleophilicity/Electron Transfer 1109 Fullerenium Cations D. Fullerides as Intermediates 1110 IV. Electronic (NIR) Spectroscopy 1082 E. Fullerides as Catalysts 1111 A. Introduction 1082 F. Fullerides as Ligands 1111 n- B. C60 Fullerides 1082 G. Fullerenium Cations 1112 C. C70 and Higher Fullerenes 1085 XI. Conclusions and Future Directions 1113 D. Fullerenium Cations 1086 XII. Acknowledgments 1114 E. Diffuse Interstellar Bands 1086 XIII. References 1114 V. Vibrational Spectroscopy 1087 A. Infrared Spectroscopy 1087 B. Raman Spectroscopy 1087 I. Introduction, Scope, and Nomenclature VI. X-ray Crystallography 1088 The electron-accepting ability of C60, the archetypal A. Introduction 1088 fullerene, is its most characteristic chemical property. 2- B. [PPN]2[C60] and Related C60 Structures 1088 It is a natural consequence of electronic structure and - C. C60 Structures 1090 was anticipated in early molecular orbital calcula- 3- 1 D. C60 Structures 1091 tions which place a low-lying unoccupied t1u level 2-4 E. Comparison of Discrete and Extended 1091 about 2 eV above the hu HOMO: Structures VII. Magnetic Susceptibility and Spin States 1092 VIII. NMR Spectroscopy 1093 A. Introduction 1093 B. 13C NMR Data in Solution 1094 C. Interpretation of Solution NMR Data 1095 D. 13C NMR Data in the Solid State 1096 E. Knight Shift in A3C60 1098 F. 3He NMR of Endohedral Fullerides 1098 G. 13C NMR of Derivatized Fullerenes 1099 Early in the gas-phase investigations of fullerenes, H. 13C NMR of Fullerenium Cations 1099 the electron affinity of C60 was measured and found IX. EPR Spectroscopy 1099 to be high (2.69 eV).5-7 When the macroscopic era of A. Introduction 1099 C60 chemistry began in 1990, this property was soon - B. Features of the C60 Spectrum 1099 found to translate into the solution phase.8 In a i. The Low g Value 1100 rather remarkable cyclic voltammogram (see Figure ii. Temperature Dependence of the Line 1100 1), the reversible stepwise addition of up to six 9,10 Width (∆Hpp) electrons was soon demonstrated electrochemically. 10.1021/cr980017o CCC: $35.00 © 2000 American Chemical Society Published on Web 02/16/2000 1076 Chemical Reviews, 2000, Vol. 100, No. 3 Reed and Bolskar Chris Reed received his education in his native land at The University of Auckland, New Zealand. His Ph.D. studies were on iridium chemistry with Warren Roper F.R.S. His postdoctoral work was on picket-fence porphyrins with Jim Collman at Stanford University. He joined the faculty at the University of Southern California in 1973, becoming Professor in 1982. Figure 1. Cathodic cyclic and differential pulse voltam- Since 1998 he has been Distinguished Professor of Chemistry at the mograms of C60 in CH3CN/toluene at -10 °C showing University of California, Riverside. His research interests include reactive 6- successive reversible reductions to C60 . (Reprinted with cation and superacid chemistry with inert carborane counterions, ionic permission from ref 9. Copyright 1992 American Chemical liquids, bioinorganic chemistry, spin-coupling phenomena, fullerene Society.) chemistry, and new carbon- or porphyrin-based materials. He is a Sloan Fellow, a Dreyfus Teacher−Scholar Awardee, and a Guggenheim Fellow. but tangential contact at near van der Waals separa- tion is sufficient to develop the appropriate electronic band structures. Under these circumstances, the electronic properties of the individual ions must be largely retained, suggesting that the electronic struc- ture of discrete fulleride ions is the preferred point of departure for understanding their extended prop- erties.17 This is one of the major reasons for studying isolated fulleride ions in detail. An example of where discrete fulleride chemistry meets materials science is in the determination of an appropriate value for the Knight shift in A3C60 metals. There are quite divergent opinions on how to partition the observed solid-state 13C NMR shifts in A3C60 compounds (185-196 ppm) into an intrinsic chemical shift and a Knight shift (i.e., the contribu- Robert Bolskar received his B.S. degree in Chemistry from Carroll College tion of the conduction electrons relative to an insu- in Waukesha, WI, in 1992. He earned his Ph.D. degree at the University lating state). Knight shifts as high as 61 ppm18 and of Southern California in Los Angeles under the direction of Christopher as low as 6 ppm19 have been suggested. The effect of Reed in 1997, investigating the synthetic redox chemistry of fullerene 3- anions and cations. In 1998 he moved to the University of California, unpaired electrons on the chemical shift in the C60 Riverside, as Managing Research Associate. He is currently Senior ion, present in both the conducting and the insulating Chemist at TDA Research in Wheat Ridge, CO. His research interests phases, has been largely neglected in the discussion. include the chemistry and physics of fullerene compounds, supramolecular Determining the correct value has significant rami- chemistry, strongly oxidizing systems, and electrophilic cations. fications for the calculated density of states at the 20 Fermi level, N(EF), in A3C60 conductors. n- However, the best known demonstration of the elec- An unanticipated property of discrete C60 ful- tronegative nature of C60 is the solid-state intercala- lerides is their propensity to disobey Hund’s rule. For tion of electropositive metals producing a large family example, the 3-fold degeneracy of the t1u LUMO leads of MxC60 salts called fullerides. The most remarkable to the expectation of a spin quartet ground state for ) 3- of these are the superconducting phases, A3C60 (A C60 : alkali metal cation).11 The extended properties of these systems have been extensively reviewed else- where12-15 but are part of this review when connec- n- tions can be made to the discrete C60 ions. Another 3- early development was the discovery of a unique ful- This is, however, not observed. C60 has a spin leride phase which displays ferromagnetism: [TDAE]- doublet ground state even though there is no require- 16 [C60] (TDAE ) tetrakis(dimethylamino)ethane). ment for a Jahn-Teller lowering of symmetry.21 2- Solid-state superconductivity and ferromagnetism There is a similar counterintuitive result with C60 in [60]-fulleride materials arises from cooperative whose electronic structure has been somewhat con- interactions between electrons on adjacent bucky- troversial. Resolving the conflicting interpretations balls. The ball-to-ball contact is relatively meager, of data and theory for this ion is one of the motiva- Discrete Fulleride Anions and Fullerenium Cations Chemical Reviews, 2000, Vol. 100, No. 3 1077 tions for compiling this review. Another is to assess for continued comprehensive development of fullerene the current status of the long-standing problem chemistry with an emphasis on the charged redox regarding the origin of the extra signals seen in the states of these novel curved-carbon structures. Donor- EPR spectra of fullerides. Of the six explanations that acceptor properties of fullerene and fulleride materi- have been offered to explain the origin of the sharp als have recently been reviewed.48 - signal (or “spike”) in the EPR spectrum of C60 , only two remain viable. Much of the early work is open to The literature on fullerenes is widely spread across reinterpretation, and we now conclude that C-C the disciplines of material science, physics, and n- n- bonded dimers of fullerides (C120O or C120 ) offer chemistry in all its branches, adding to the challenge the most compelling explanation for the extra signals. of writing a review that is both critical and compre- 22 23 Dimeric and polymeric AC60 phases containing hensive. Compounding this is the proliferation of C-C bonded fullerides have become quite well char- publications associated with conferences which, apart acterized in recent years. from sometimes undesirable duplication, may intro- Related to the idea of C-C bonded dimers is the duce data and interpretations that have not had the very recent finding that the newly recognized class benefit of thorough peer review. We take such data 49 of low HOMO-LUMO gap fullerenes (C74,C80, etc.), cum grano salis and make no claims of being trapped in fullerene soot because of polymerization, comprehensive in the coverage of conference-related can be solubilized by reduction to discrete anions.24 literature. There is also the relationship of fullerides to endohe- As its point of departure, the recommended no- dral metallofullerenes, M@C . The electropositive 2n menclature for fullerenes50 seems to have adopted the nature of the metals that form endohedral fullerenes means that their carbon frameworks must have a dubious assumption that fullerenes are dehydroge- high degree of fulleride character.25-28 Although they nated hydrocarbons rather than a unique class of are not yet available in large quantities, there are molecules in their own right.
Load more

Recommended publications
  • Process for Producing a Metal Fulleride
    Europäisches Patentamt *EP001199281A1* (19) European Patent Office Office européen des brevets (11) EP 1 199 281 A1 (12) EUROPEAN PATENT APPLICATION (43) Date of publication: (51) Int Cl.7: C01B 31/02 24.04.2002 Bulletin 2002/17 (21) Application number: 00122854.3 (22) Date of filing: 20.10.2000 (84) Designated Contracting States: • Dubitzky, Yuri A. AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU 20159 Milano (IT) MC NL PT SE • Ricco, Mauro Designated Extension States: 43100 Parma (IT) AL LT LV MK RO SI • Sartori, Andrea 43010 Fontana (Parma) (IT) (71) Applicant: PIRELLI CAVI E SISTEMI S.p.A. 20126 Milano (IT) (74) Representative: Giannesi, Pier Giovanni et al Pirelli S.p.A. (72) Inventors: Industrial Property Dept. • Zaopo, Antonio Viale Sarca, 222 20137 Milano (IT) 20126 Milano (IT) (54) Process for producing a metal fulleride (57) The present invention relates to a process for acting in a liquid medium: 1) a first metal fulleride having, producing a metal fulleride. In particular, the present in- as counterion, a cation of a first metal forming a salt sub- vention relates to a process for producing a metal ful- stantially insoluble in said liquid medium, and 2) a salty leride by an ion exchange reaction in a liquid medium, of a second metal substantially soluble in said liquid me- preferably in liquid ammonia. More particularly, the dium, so as to produce a second metal fulleride having, present invention relates to a process for producing a as counterion, a cation of said second metal.
    [Show full text]
  • Discrete Fulleride Anions and Fullerenium Cations
    UC Riverside UC Riverside Previously Published Works Title Discrete fulleride anions and fullerenium cations. Permalink https://escholarship.org/uc/item/60b5m71z Journal Chemical reviews, 100(3) ISSN 0009-2665 Authors Reed, CA Bolskar, RD Publication Date 2000-03-01 DOI 10.1021/cr980017o Peer reviewed eScholarship.org Powered by the California Digital Library University of California Chem. Rev. 2000, 100, 1075−1120 1075 Discrete Fulleride Anions and Fullerenium Cations Christopher A. Reed* and Robert D. Bolskar Department of Chemistry, University of CaliforniasRiverside, Riverside, California 92521-0403 Received June 22, 1999 Contents iii. Anisotropy 1100 iv. Problem of the Sharp Signals 1101 I. Introduction, Scope, and Nomenclature 1075 v. Origins of Sharp Signals 1102 II. Electrochemistry 1078 vi. The C O Impurity Postulate 1103 A. Reductive Voltammetry 1078 120 vii. The Dimer Postulate 1104 B. Oxidative Voltammetry 1079 2- C. Features of the C60 EPR Spectrum 1106 III. Synthesis 1079 3- D. Features of the C60 EPR Spectrum 1107 A. Chemical Reduction of Fullerenes to 1079 4- 5- Fullerides E. Features of C60 and C60 EPR Spectra 1107 i. Metals as Reducing Agents 1080 F. EPR Spectra of Higher Fullerides 1107 ii. Coordination and Organometallic 1080 G. EPR Spectra of Fullerenium Cations 1108 Compounds as Reducing Agents X. Chemical Reactivity 1108 iii. Organic/Other Reducing Agents 1081 A. Introduction 1108 B. Electrosynthesis of Fullerides 1081 B. Fulleride Basicity 1109 C. Chemical Oxidation of Fullerenes to 1081 C. Fulleride Nucleophilicity/Electron Transfer 1109 Fullerenium Cations D. Fullerides as Intermediates 1110 IV. Electronic (NIR) Spectroscopy 1082 E. Fullerides as Catalysts 1111 A. Introduction 1082 F.
    [Show full text]
  • Electrochemical Synthesis of Lithium Fullerides
    Chem. Met. Alloys 6 (2013) 40-42 Ivan Franko National University of Lviv www.chemetal-journal.org Electrochemical synthesis of lithium fullerides A.O. ZUL’FIGAROV 1, V.A. POTASKALOV 1, A.P. POMYTKIN 1, A.A. ANDRIIKO 1*, D.V. SHCHUR 2, O.A. KRIUKOVA 3, V.G. KHOMENKO 3 1 Chair of General and Inorganic Chemistry, National Technical University of Ukraine “Kyiv Polytechnic Institute”, 37 Prospekt Peremogy, Kyiv, Ukraine 2 Institute of Material Science Problems, National Academy of Sciences of Ukraine, 3 Krzhyzhanovskogo St., Kyiv, Ukraine 3 National University of Technologies and Design, 2 Nemyrovycha-Danchenka St., Kyiv, Ukraine * Corresponding author. E-mail: [email protected] Received June 3, 2013; accepted June 19, 2013; available on-line November 4, 2013 The electrochemical reaction of Li with fullerene in an aprotic electrolyte was studied. It was found that a lithium-rich fulleride with approximate formula Li 10 C60 can be obtained in the presence of a catalyst. This amount of Li is irreversibly incorporated into the structure. Additionally, 4-5 atoms can be introduced reversibly, thus allowing cycling the material with an initial reversible capacity of about 180 mAh·g -1. The pyrolysis product of a heterometal complex with monoaminoethanol ligands is shown to be a good catalyst for this process. Fullerene / Lithium fulleride / Electrochemical synthesis Introduction The cathodic reduction of Li + ions on a fullerene- based electrode under controlled current was chosen Since the discovery of carbon allotrope fullerenes in for this purpose. In some of the experiments, the 1985 [1] , a large number of researches have been electrode contained additives of a trinuclear complex devoted to the chemistry of these substances.
    [Show full text]
  • Hydrocarbon-Soluble, Hexaanionic Fulleride Complexes of Magnesium† Cite This: Chem
    Chemical Science View Article Online EDGE ARTICLE View Journal | View Issue Hydrocarbon-soluble, hexaanionic fulleride complexes of magnesium† Cite this: Chem. Sci.,2019,10,10755 a b a All publication charges for this article Samuel R. Lawrence, C. Andre´ Ohlin, David B. Cordes, have been paid for by the Royal Society Alexandra M. Z. Slawin a and Andreas Stasch *a of Chemistry Ar Ar The reaction of the magnesium(I) complexes [{( nacnac)Mg}2], ( nacnac ¼ HC(MeCNAr)2,Ar¼ Dip (2,6- iPr2C6H3), Dep (2,6-Et2C6H3), Mes (2,4,6-Me3C6H2), Xyl (2,6-Me2C6H3)) with fullerene C60 afforded Ar a series of hydrocarbon-soluble fulleride complexes [{( nacnac)Mg}nC60], predominantly with n ¼ 6, 4 and 2. 13C{1H} NMR spectroscopic studies show both similarities (n ¼ 6) and differences (n ¼ 4, 2) to previously characterised examples of fulleride complexes and materials with electropositive metal ions. Ar The molecular structures of [{( nacnac)Mg}nC60] with n ¼ 6, 4 and 2 can be described as inverse Ar + nÀ coordination complexes of n [( nacnac)Mg] ions with C60 anions showing predominantly ionic 6À metal–ligand interactions, and include the first well-defined and soluble complexes of the C60 ion. Ar + 6À Experimental studies show the flexible ionic nature of the {( nacnac)Mg} /C60 coordination bonds. Creative Commons Attribution 3.0 Unported Licence. Received 2nd August 2019 DFT calculations on the model complex [{(Menacnac)Mg} C ](Menacnac ¼ HC(MeCNMe) ) support the Accepted 6th October 2019 6 60 2 6À 6À formulation as an ionic complex with a central C60 anion and comparable frontier orbitals to C60 DOI: 10.1039/c9sc03857d with a small HOMO–LUMO gap.
    [Show full text]
  • INFORMATION to USERS This Manuscript Has Been Reproduced
    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 face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely 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. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand comer and continuing from left to right in equal sections with small overlaps. Each original is also photographed in one exposure and is included in reduced form at the back of the book. Photographs included in the original manuscript have been reproduced xerographically in this copy. Higher quality 6" x 9" black and white photographic prints are available for any photographs or illustrations appearing in this copy for an additional charge. Contact UMI directly to order. A Bell & Howell information Company 300 North Zeeb Road. Ann Arbor. Ml 48106-1346 USA 313/761-4700 800/521-0600 NMR Studies of Alkali Fulleride Superconductors DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in the Graduate School of The Ohio State University By Victor A.
    [Show full text]
  • Tuneable Graphite Intercalates for Hydrogen Storage
    Tuneable graphite intercalates for hydrogen storage Arthur Lovell A Thesis presented for the degree of Doctor of Philosophy Condensed Matter and Materials Physics Department of Physics and Astronomy University College London England September 2007 Declaration I, Arthur Lovell, con¯rm that the work presented in this thesis is my own. Where information has been derived from other sources, I con¯rm that this has been indicated in the thesis. The work in this thesis is based on research carried out at the Condensed Matter and Materials Physics Group, the Department of Physics and Astronomy, University College London, England. No part of this thesis has been submitted elsewhere for any other degree or quali¯cation. Copyright °c 2007 by Arthur Lovell. \The copyright of this thesis rests with the author. No quotations from it should be published without the author's prior written consent and information derived from it should be acknowledged". ii Tuneable graphite intercalates for hydrogen storage Arthur Lovell Submitted for the degree of Doctor of Philosophy September 2007 Abstract The development of hydrogen as an energy transfer mechanism is of great importance to alleviate environmental damage and economic destabilisation caused by over-reliance on oil, as long as the hydrogen can be generated re- newably. To be suitable for road transport applications, safe and compact hydrogen storage systems need to be developed, the primary technological motivation for this PhD project which investigates hydrogen absorbed into graphite intercalation compounds (GICs), to gain a fundamental physical un- derstanding of the sorption processes to improve such materials' capacity for hydrogen storage.
    [Show full text]
  • Coexistence of Full-Gap Superconductivity and Pseudogap in Two-Dimensional Fullerides
    Coexistence of full-gap superconductivity and pseudogap in two-dimensional fullerides Ming-Qiang Ren1, Sha Han1, Shu-Ze Wang1, Jia-Qi Fan1, Can-Li Song1,2 †, Xu-Cun Ma1,2 †, Qi-Kun Xue1,2,3† 1 State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China 2 Frontier Science Center for Quantum Information, Beijing 100084, China 3 Beijing Academy of Quantum Information Sciences, Beijing 100193, China Alkali-fulleride superconductors with a maximum critical temperature Tc 40 K exhibit similar 1-5 electronic phase diagram with unconventional high-Tc superconductors where the superconductivity resides proximate to a magnetic Mott-insulating state3-6. However, distinct 7 from cuprate compounds, which superconduct through two-dimensional (2D) CuO2 planes , 8,9 alkali fullerides are attributed to the three-dimensional (3D) members of high-Tc family . Here, we employ scanning tunneling microscopy (STM) to show that trilayer K3C60 displays fully gapped strong coupling s-wave superconductivity that coexists spatially with a cuprate-like pseudogap state above Tc 22 K and within vortices. A precise control of electronic correlations and doping reveals that superconductivity occurs near a superconductor-Mott insulator transition (SMIT) and reaches maximum at half-filling. The s-wave symmetry retains over the entire phase diagram, which, in conjunction with an abrupt decline of superconductivity below half-filling, demonstrates that alkali fullerides are predominantly phonon-mediated superconductors, although the multiorbital electronic correlations also come into play. †To whom correspondence should be addressed. Email: [email protected], [email protected], [email protected] 1 10,11 Trivalent fullerides A3C60 (A = alkali metals) have historically been, albeit not universally , thought of as conventional Bardeen-Cooper-Schrieffer (BCS) superconductors12,13.
    [Show full text]
  • Heavy Alkali-Metal Intercalated Fullerenes Under High Pressure and High Temperature Conditions: Rb6c60 and Cs6c60 Roberta Poloni
    Heavy alkali-metal intercalated fullerenes under high pressure and high temperature conditions: Rb6C60 and Cs6C60 Roberta Poloni To cite this version: Roberta Poloni. Heavy alkali-metal intercalated fullerenes under high pressure and high temperature conditions: Rb6C60 and Cs6C60. Physics [physics]. Université Claude Bernard - Lyon I, 2007. English. tel-00194610 HAL Id: tel-00194610 https://tel.archives-ouvertes.fr/tel-00194610 Submitted on 6 Dec 2007 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. No d'ordre 214{2007 Ann´ee 2007 THESE` pr´esent´ee devant l'UNIVERSITE´ CLAUDE BERNARD - LYON 1 pour l'obtention du DIPLOME DE DOCTORAT arr^et´e du 7 aout^ 2006 pr´esent´ee et soutenue publiquement le 31 Octobre 2007 par Roberta POLONI TITRE: Heavy alkali metal-intercalated fullerenes under high pressure and high temperature conditions: Rb6C60 and Cs6C60 Directeur de th`ese Prof. Alfonso SAN MIGUEL JURY: Pascale Launois Rapporteur Bertil Sundqvist Rapporteur Xavier Blase Pr´esident Marco Saitta Examinateur Kosmas Prassides Examinateur Alfonso San Miguel Directeur Sakura Pascarelli Codirecteur 2 Contents Introduction i 1 The C60 fullerene and the heavy alkali metal-intercalated fullerenes 1 1.1 Motivation .
    [Show full text]
  • Merohedral Disorder and Impurity Impacts on Superconductivity of Fullerenes
    Merohedral disorder and impurity impacts on superconductivity of fullerenes Shu-Ze Wang1*, Ming-Qiang Ren1*, Sha Han1, Fang-Jun Cheng1, Xu-Cun Ma1,2, Qi-Kun Xue1,2,3,4, Can-Li Song1,2† 1State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China 2Frontier Science Center for Quantum Information, Beijing 100084, China 3Beijing Academy of Quantum Information Sciences, Beijing 100193, China 4Southern University of Science and Technology, Shenzhen 518055, China Local quasiparticle states around impurities provide essential insight into the mechanism of unconventional superconductivity, especially when the candidate materials are proximate to an antiferromagnetic Mott-insulating phase. While such states have been reported in atom- based cuprates and iron-based compounds, they are unexplored in organic superconductors which feature tunable molecular orientation. Here we employ scanning tunneling microscopy and spectroscopy to reveal multiple forms of robustness of an exotic s-wave superconductivity in epitaxial Rb3C60 films against merohedral disorder, non-magnetic single impurities and step edges at the atomic scale. Also observed have been Yu-Shiba-Rusinov (YSR) states induced by deliberately incurred Fe adatoms that act as magnetic scatterers. The bound states display abrupt spatial decay and vary in energy with the Fe adatom registry. Our results and the universal optimal superconductivity at half-filling point towards local electron pairing in which the multiorbital electronic correlations and intramolecular phonons together drive the high- temperature superconductivity of doped fullerenes. *Both authors contributed equally to this work. 1 †To whom correspondence should be addressed. Email: [email protected] 2 Disorder, impurities in an otherwise homogeneous superconductor, are often undesired aliens because they may hinder observations of intrinsic properties of the host material1-3.
    [Show full text]
  • University of London Thesis
    REFERENCE ONLY UNIVERSITY OF LONDON THESIS Degree Year Name of Author C~ A C O P Y R IG H T This is a thesis accepted for a Higher Degree of the University of London. It is an unpublished typescript and the copyright is held by the author. All persons consulting the thesis must read and abide by the Copyright Declaration below. COPYRIGHT DECLARATION I recognise that the copyright of the above-described thesis rests with the author and that no quotation from it or information derived from it may be published without the prior written consent of the author. LOANS Theses may not be lent to individuals, but the Senate House Library may lend a copy to approved libraries within the United Kingdom, for consultation solely on the premises of those libraries. Application should be made to: Inter-Library Loans, Senate House Library, Senate House, Malet Street, London WC1E 7HU. REPRODUCTION University of London theses may not be reproduced without explicit written permission from the Senate House Library. Enquiries should be addressed to the Theses Section of the Library. Regulations concerning reproduction vary according to the date of acceptance of the thesis and are listed below as guidelines. A. Before 1962. Permission granted only upon the prior written consent of the author. (The Senate House Library will provide addresses where possible). B. 1962- 1974. In many cases the author has agreed to permit copying upon completion of a Copyright Declaration. C. 1975 - 1988. Most theses may be copied upon completion of a Copyright Declaration. D. 1989 onwards. Most theses may be copied.
    [Show full text]
  • Superconductivity, High Temperature Superconductivity
    SUPERCONDUCTIVITY, HIGH TEMPERATURE SUPERCONDUCTIVITY Magnetization relaxation in superconducting fulleride K3C60 single crystals V. A. Buntar, F. M. Sauerzopf, and H. W. Weber Atominstitut der O¨ sterreichischen Universita¨ten, A-1020 Wien, Austria A. G. Buntar Vinnitsa State Technical University, 286021 Vinnitsa, Ukraine H. Kumani and M. Haluska Institut fu¨r Festko¨rperphysik, Universita¨t Wien, A-1090 Wien, Austria ~Submitted September 10, 1996! Fiz. Nizk. Temp. 23, 365–371 ~April 1997! Magnetic relaxation processes in superconducting fulleride K3C60 are investigated on monocrystalline samples in a wide range of temperatures and magnetic fields. A logarithmic time dependence M(t) of magnetization is observed in samples with 100% of superconducting phase. The normalized relaxation rate increases with temperature in the entire range of magnetic fields. The flux creep activation energy ranges from 10 to 80 meV, and its temperature dependence has a peak. It has been concluded from the results of measurements on samples with nonideal stoichiometry that inhomogeneities strongly affect the relaxation processes and can mask the logarithmic dependence M(t) completely. © 1997 American Institute of Physics. @S1063-777X~97!00104-7# 1. INTRODUCTION also observed in fullerides. However, these two types of su- perconductors exhibit considerable differences. Supercon- The measurements of relaxation magnetization serve as ductivity in HTS compounds is two-dimensional and a universal method for studying irreversible properties of strongly anisotropic, while FS are three-dimensional super- type II superconductors and provide information on pinning conductors with a cubic lattice. of Abrikosov vortices, their dynamic properties, the nature of Thus, an analysis of time relaxation of magnetization in kinetic state, and so on.
    [Show full text]
  • Chem Rev Accepted Manuscript.Pdf
    This is a repository copy of Harnessing the Synergistic and Complementary Properties of Fullerene and Transition-Metal Compounds for Nanomaterial Applications. White Rose Research Online URL for this paper: http://eprints.whiterose.ac.uk/92012/ Version: Accepted Version Article: Lebedeva, MA, Chamberlain, TW and Khlobystov, AN (2015) Harnessing the Synergistic and Complementary Properties of Fullerene and Transition-Metal Compounds for Nanomaterial Applications. Chemical Reviews, 115 (20). 11301 - 11351. ISSN 0009-2665 https://doi.org/10.1021/acs.chemrev.5b00005 Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version - refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher’s website. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. [email protected] https://eprints.whiterose.ac.uk/ Harnessing the synergistic and complementary properties of fullerene and transition metal compounds for nanomaterial applications. Maria A. Lebedevaa, Thomas W. Chamberlaina, and Andrei N. Khlobystov*a,b. aSchool of Chemistry, University of Nottingham, Nottingham, NG7 2RD, UK bNottingham Nanotechnology & Nanoscience Centre, University of Nottingham, University Park, Nottingham, NG7 2RD, UK.
    [Show full text]