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Electron Spin Relaxation in Carbon Materials. MATERIALS 2022; 15:ma15144964. [PMID: 35888431 PMCID: PMC9318273 DOI: 10.3390/ma15144964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/05/2022] [Accepted: 07/14/2022] [Indexed: 11/17/2022]
Abstract
This article focuses on EPR relaxation measurements in various carbon samples, e.g., natural carbons-anthracite, coal, higher anthraxolites, graphite; synthetically obtained carbons-glassy carbons, fullerenes, graphene, graphene oxide, reduced graphene oxide, graphite monocrystals, HOPG, nanoribbons, diamonds. The short introduction presents the basics of resonant electron spin relaxation techniques, briefly describing the obtained parameters. This review presents gathered results showing the processes leading to electron spin relaxation and typical ranges of electron spin relaxation rates for many different carbon types.
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Niklas J, Mardis KL, Poluektov OG. Spin Signature of the C 60 Fullerene Anion: A Combined X- and D-Band EPR and DFT Study. J Phys Chem Lett 2018; 9:3915-3921. [PMID: 29969036 PMCID: PMC6563802 DOI: 10.1021/acs.jpclett.8b01613] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Fullerenes attract much attention in various scientific fields, but their electronic properties are still not completely understood. Here we report on a combined EPR and DFT study of the fullerene anion C60- in solid glassy environment. DFT calculations were used to characterize its electronic structure through spin density distribution and magnetic resonance parameters. The electron spin density is not uniformly distributed throughout the C60- cage but shows a pattern similar to PC61BM-. EPR spectroscopy reveals a rhombic g-tensor sensitive to the environment in the frozen glassy solutions, which can be rationalized by deformation of the fullerenes along low-frequency vibrational modes upon cooling. DFT modeling confirms that these deformations lead to variation in the C60- g values. The decrease in g-tensor anisotropy with sample annealing is related to the lessening of g-tensor strain upon temperature relaxation of the most distorted sites in the glassy state.
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Affiliation(s)
- Jens Niklas
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Kristy L. Mardis
- Department of Chemistry, Physics, and Engineering Studies, Chicago State University, Chicago, Illinois 60628, USA
| | - Oleg G. Poluektov
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
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Kundu K, Kattnig DR, Mladenova B, Grampp G, Das R. Electron Spin Relaxation of C60 Monoanion in Liquid Solution: Applicability of Kivelson–Orbach Mechanism. J Phys Chem A 2015; 119:3200-8. [DOI: 10.1021/jp5126409] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Krishnendu Kundu
- Tata Institute
of Fundamental Research, Homi Bhabha
Road, Mumbai 400005, India
| | - Daniel R. Kattnig
- Physical
and Theoretical Chemistry Laboratory, University of Oxford, South Parks
Road, Oxford OX1 3QZ, United Kingdom
| | - Boryana Mladenova
- Institute
of Physical and Theoretical Chemistry, Graz University of Technology, Stremayrgasse 9/Z2, A-8010 Graz, Austria
| | - Günter Grampp
- Institute
of Physical and Theoretical Chemistry, Graz University of Technology, Stremayrgasse 9/Z2, A-8010 Graz, Austria
| | - Ranjan Das
- Tata Institute
of Fundamental Research, Homi Bhabha
Road, Mumbai 400005, India
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Martins MAP, Frizzo CP, Tier AZ, Moreira DN, Zanatta N, Bonacorso HG. Update 1 of: Ionic Liquids in Heterocyclic Synthesis. Chem Rev 2014; 114:PR1-70. [DOI: 10.1021/cr500106x] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Marcos A. P. Martins
- Núcleo de Química
de Heterociclos (NUQUIMHE), Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria-RS, Brazil
| | - Clarissa P. Frizzo
- Núcleo de Química
de Heterociclos (NUQUIMHE), Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria-RS, Brazil
| | - Aniele Z. Tier
- Núcleo de Química
de Heterociclos (NUQUIMHE), Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria-RS, Brazil
| | - Dayse N. Moreira
- Núcleo de Química
de Heterociclos (NUQUIMHE), Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria-RS, Brazil
| | - Nilo Zanatta
- Núcleo de Química
de Heterociclos (NUQUIMHE), Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria-RS, Brazil
| | - Helio G. Bonacorso
- Núcleo de Química
de Heterociclos (NUQUIMHE), Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria-RS, Brazil
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Martins MAP, Frizzo CP, Moreira DN, Zanatta N, Bonacorso HG. Ionic liquids in heterocyclic synthesis. Chem Rev 2008; 108:2015-50. [PMID: 18543878 DOI: 10.1021/cr078399y] [Citation(s) in RCA: 480] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Marcos A P Martins
- Núcleo de Química de Heterociclos (NUQUIMHE), Departamento de Química , Universidade Federal de Santa Maria, 97105-900 Santa Maria-RS, Brazil.
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Affiliation(s)
- Marcos A. P. Martins
- Núcleo de Química de Heterociclos (NUQUIMHE), Departamento de Química , Universidade Federal de Santa Maria, 97105-900 Santa Maria-RS, Brazil
| | - Clarissa P. Frizzo
- Núcleo de Química de Heterociclos (NUQUIMHE), Departamento de Química , Universidade Federal de Santa Maria, 97105-900 Santa Maria-RS, Brazil
| | - Dayse N. Moreira
- Núcleo de Química de Heterociclos (NUQUIMHE), Departamento de Química , Universidade Federal de Santa Maria, 97105-900 Santa Maria-RS, Brazil
| | - Nilo Zanatta
- Núcleo de Química de Heterociclos (NUQUIMHE), Departamento de Química , Universidade Federal de Santa Maria, 97105-900 Santa Maria-RS, Brazil
| | - Helio G. Bonacorso
- Núcleo de Química de Heterociclos (NUQUIMHE), Departamento de Química , Universidade Federal de Santa Maria, 97105-900 Santa Maria-RS, Brazil
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Zoleo A, Bellinazzi M, Prato M, Brustolon M, Maniero AL. Multifrequency EPR study and DFT calculations of a C60 bisadduct anion. Chem Phys Lett 2005. [DOI: 10.1016/j.cplett.2005.07.047] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Drew SC, Boas JF, Pilbrow JR, Boyd PDW, Paul P, Reed CA. Spin States of C603- and C120On- (n = 2, 3, 4) Anions Using Electron Spin Transient Nutation Spectroscopy. J Phys Chem B 2003. [DOI: 10.1021/jp035632x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Simon C. Drew
- School of Physics and Materials Engineering, Building 27, Monash University, Victoria 3800, Australia, Department of Chemistry, University of Auckland, New Zealand Private Bag 92019, Auckland, New Zealand, and Department of Chemistry, University of California, Riverside, California 92521-0403
| | - John F. Boas
- School of Physics and Materials Engineering, Building 27, Monash University, Victoria 3800, Australia, Department of Chemistry, University of Auckland, New Zealand Private Bag 92019, Auckland, New Zealand, and Department of Chemistry, University of California, Riverside, California 92521-0403
| | - John R. Pilbrow
- School of Physics and Materials Engineering, Building 27, Monash University, Victoria 3800, Australia, Department of Chemistry, University of Auckland, New Zealand Private Bag 92019, Auckland, New Zealand, and Department of Chemistry, University of California, Riverside, California 92521-0403
| | - Peter D. W. Boyd
- School of Physics and Materials Engineering, Building 27, Monash University, Victoria 3800, Australia, Department of Chemistry, University of Auckland, New Zealand Private Bag 92019, Auckland, New Zealand, and Department of Chemistry, University of California, Riverside, California 92521-0403
| | - Parimal Paul
- School of Physics and Materials Engineering, Building 27, Monash University, Victoria 3800, Australia, Department of Chemistry, University of Auckland, New Zealand Private Bag 92019, Auckland, New Zealand, and Department of Chemistry, University of California, Riverside, California 92521-0403
| | - Christopher A. Reed
- School of Physics and Materials Engineering, Building 27, Monash University, Victoria 3800, Australia, Department of Chemistry, University of Auckland, New Zealand Private Bag 92019, Auckland, New Zealand, and Department of Chemistry, University of California, Riverside, California 92521-0403
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Stevenson CD, Noyes JR, Reiter RC. Condensation Products from the Anionic Radicals of C 60 and the Common Solvent: Hexamethylphosphoramide. J Phys Chem B 2002. [DOI: 10.1021/jp026591s] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Cheryl D. Stevenson
- Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160
| | - James R. Noyes
- Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160
| | - Richard C. Reiter
- Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160
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Paul P, Kim KC, Sun D, Boyd PDW, Reed CA. Artifacts in the electron paramagnetic resonance spectra of C60 fullerene ions: inevitable C120O impurity. J Am Chem Soc 2002; 124:4394-401. [PMID: 11960468 DOI: 10.1021/ja011832f] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Aspects of the electron paramagnetic resonance (EPR) spectra of C60n- fulleride ions (n = 2, 3) and the EPR signal observed in solid C60 are reinterpreted. Insufficient levels of reduction and the unrecognized presence of C120O, a ubiquitous and unavoidable impurity in air-exposed C60, have compromised most previously reported spectra of fullerides. Central narrow line width signals ("spikes") are ascribed to C120On- (n = odd). Signals arising from axial triplets (g approximately 2.0015, D = 26-29 G) in the spectrum of C602- are ascribed to C120On- (n = 2 or 4). Their D values are more realistic for C120O than C60. Less distinct signals from "powder" triplets (D approximately 11 G) are ascribed to aggregates of C120On- (n = odd) arising from freezing nonglassing solvents. In highly purified samples of C60, we find no evidence for a broad approximately 30 G signal previously assigned to a thermally accessible triplet of C60(2-). The C60(2-) ion is EPR-silent. Signals previously ascribed to a quartet state of the C60(3-) ion are ascribed to C120O4-. Uncomplicated, authentic spectra of C60- and C60(3-) become available when fully reduced samples are prepared under strictly anaerobic conditions from freshly HPLC-purified C60. Solid off-the-shelf C60 has an EPR signal (g approximately 2.0025, DeltaH(pp) approximately 1.5 G) that is commonly ascribed to the radical cation C60*+. This signal can be reproduced by exposing highly purified, EPR-silent C60 to oxygen in the dark. Doping C60 with an authentic C60*+ salt gives a signal with much greater line width (DeltaH(pp) = 6-8 G). It is suggested that the EPR signal in air-exposed samples of C60 arises from a peroxide-bridged diradical, *C60-O-O-C60* or its decomposition products rather than from C60*+. Solid-state C60 is more sensitive to oxygen than previously appreciated such that contamination with C120O is almost impossible to avoid.
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Affiliation(s)
- Parimal Paul
- Department of Chemistry, University of California, Riverside, California 92521-0403, USA
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Eaton SS, Eaton GR. Relaxation Times of Organic Radicals and Transition Metal Ions. DISTANCE MEASUREMENTS IN BIOLOGICAL SYSTEMS BY EPR 2002. [DOI: 10.1007/0-306-47109-4_2] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Fässler TF. The renaissance of homoatomic nine-atom polyhedra of the heavier carbon-group elements Si–Pb. Coord Chem Rev 2001. [DOI: 10.1016/s0010-8545(01)00321-6] [Citation(s) in RCA: 171] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Fukuzumi S, Mori H, Suenobu T, Imahori H, Gao X, Kadish KM. Effects of Lowering Symmetry on the ESR Spectra of Radical Anions of Fullerene Derivatives and the Reduction Potentials. J Phys Chem A 2000. [DOI: 10.1021/jp002375c] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shunichi Fukuzumi
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, CREST, Japan Science and Technology Corporation, Suita, Osaka 565-0871, Japan, and Department of Chemistry, University of Houston, Houston, Texas 77204-5641
| | - Hisahiro Mori
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, CREST, Japan Science and Technology Corporation, Suita, Osaka 565-0871, Japan, and Department of Chemistry, University of Houston, Houston, Texas 77204-5641
| | - Tomoyoshi Suenobu
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, CREST, Japan Science and Technology Corporation, Suita, Osaka 565-0871, Japan, and Department of Chemistry, University of Houston, Houston, Texas 77204-5641
| | - Hiroshi Imahori
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, CREST, Japan Science and Technology Corporation, Suita, Osaka 565-0871, Japan, and Department of Chemistry, University of Houston, Houston, Texas 77204-5641
| | - Xiang Gao
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, CREST, Japan Science and Technology Corporation, Suita, Osaka 565-0871, Japan, and Department of Chemistry, University of Houston, Houston, Texas 77204-5641
| | - Karl M. Kadish
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, CREST, Japan Science and Technology Corporation, Suita, Osaka 565-0871, Japan, and Department of Chemistry, University of Houston, Houston, Texas 77204-5641
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Zoleo A, Maniero AL, Prato M, Severin MG, Brunel LC, Kordatos K, Brustolon M. Anion Radicals of Mono- and Bisfulleropyrrolidines: g Tensors, Spin Density Distribution and Spin−Lattice Relaxation. J Phys Chem A 2000. [DOI: 10.1021/jp001518s] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alfonso Zoleo
- Dipartimento di Chimica Fisica, Universitá di Padova, Via Loredan 2, I-35131 Padova, Italy, and Dipartimento di Scienze Farmaceutiche, Universitá di Trieste, Piazzale Europa, 34100 Trieste, Italy, and Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306
| | - Anna Lisa Maniero
- Dipartimento di Chimica Fisica, Universitá di Padova, Via Loredan 2, I-35131 Padova, Italy, and Dipartimento di Scienze Farmaceutiche, Universitá di Trieste, Piazzale Europa, 34100 Trieste, Italy, and Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306
| | - Maurizio Prato
- Dipartimento di Chimica Fisica, Universitá di Padova, Via Loredan 2, I-35131 Padova, Italy, and Dipartimento di Scienze Farmaceutiche, Universitá di Trieste, Piazzale Europa, 34100 Trieste, Italy, and Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306
| | - Maria Gabriella Severin
- Dipartimento di Chimica Fisica, Universitá di Padova, Via Loredan 2, I-35131 Padova, Italy, and Dipartimento di Scienze Farmaceutiche, Universitá di Trieste, Piazzale Europa, 34100 Trieste, Italy, and Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306
| | - Louis Claude Brunel
- Dipartimento di Chimica Fisica, Universitá di Padova, Via Loredan 2, I-35131 Padova, Italy, and Dipartimento di Scienze Farmaceutiche, Universitá di Trieste, Piazzale Europa, 34100 Trieste, Italy, and Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306
| | - Konstantinos Kordatos
- Dipartimento di Chimica Fisica, Universitá di Padova, Via Loredan 2, I-35131 Padova, Italy, and Dipartimento di Scienze Farmaceutiche, Universitá di Trieste, Piazzale Europa, 34100 Trieste, Italy, and Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306
| | - Marina Brustolon
- Dipartimento di Chimica Fisica, Universitá di Padova, Via Loredan 2, I-35131 Padova, Italy, and Dipartimento di Scienze Farmaceutiche, Universitá di Trieste, Piazzale Europa, 34100 Trieste, Italy, and Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306
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Bond AM, Miao W, Raston CL, Sandoval CA. Electrochemical, EPR, and Magnetic Studies on Microcrystals of the [C60⊂(p-Benzyl-calix[5]arene)2]•8Toluene and Its One-Electron-Reduced Encapsulation Complex. J Phys Chem B 2000. [DOI: 10.1021/jp0017442] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alan M. Bond
- Department of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Wujian Miao
- Department of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Colin L. Raston
- Department of Chemistry, Monash University, Clayton, Victoria 3800, Australia
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Fässler T, Hoffmann R, Hoffmann S, Wörle M. Tripeldeckerartige Koordination eines Fulleren-Trianions in [K([18]krone-6)]3[η6,η6-C60](η3-C6H5CH3)2 – Einkristall-Strukturbestimmung und magnetische Eigenschaften. Angew Chem Int Ed Engl 2000. [DOI: 10.1002/1521-3757(20000616)112:12<2170::aid-ange2170>3.0.co;2-a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Alkali-metal fullerides MC60 (THF)x (M=Li, Na, K): a new solution-phase method for the preparation and characterization with ESR, UV–NIR and IR spectroscopy. J Organomet Chem 2000. [DOI: 10.1016/s0022-328x(99)00755-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Affiliation(s)
- C A Reed
- Department of Chemistry, University of California-Riverside, Riverside, California 92521-0403
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Wei X, Suo Z, Yin G, Xu Z. Alkali-earth metal fullerides Ca(C60)2 and Ba(C60)2: a new solution-phase method for the preparation and characterization with ESR, UV–NIR, IR and Raman spectroscopy. Chem Phys Lett 1999. [DOI: 10.1016/s0009-2614(99)00734-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Zhou Y, Bowler BE, Eaton GR, Eaton SS. Electron spin lattice relaxation rates for S = 12 molecular species in glassy matrices or magnetically dilute solids at temperatures between 10 and 300 K. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 1999; 139:165-174. [PMID: 10388595 DOI: 10.1006/jmre.1999.1763] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The temperature dependence of X-band electron spin-lattice relaxation between about 10 and 300 K in magnetically dilute solids and up to the softening temperature in glassy solvents was analyzed for three organic radicals and 14 S = 12 transition metal complexes. Contributions from the direct, Raman, local vibrational mode, thermally activated, and Orbach processes were considered. For most samples it was necessary to include more than one process to fit the experimental data. Debye temperatures were between 50 and 135 K. For small molecules the Debye temperature required to fit the relaxation data was higher in 1:1 water:glycerol than in organic solvents. For larger molecules the Debye temperature was less dependent upon solvent and more dependent upon the characteristics of the molecule. The coefficients of the Raman process increased with increasing g anisotropy and decreasing rigidity of the molecule. For the transition metal complexes the data are consistent with major contributions from local modes with energies in the range of 185 to 350 K (130 to 240 cm-1). The coefficient for this contribution increases in the order 3d < 4d transition metal. For C-60 anions there is a major contribution from a thermally activated process with an activation energy of about 240 cm-1. For low-spin hemes the dominant contribution at higher temperatures is from a local mode or thermally activated process with a characteristic energy of about 175 cm-1.
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Affiliation(s)
- Y Zhou
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208, USA
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Eaton GR, Eaton SS. Solvent and temperature dependence of spin echo dephasing for chromium(V) and vanadyl complexes in glassy solution. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 1999; 136:63-68. [PMID: 9887290 DOI: 10.1006/jmre.1998.1610] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The solvent and temperature dependence of the rate constant for spin echo dephasing, 1/Tm, for 0.2 to 1.2 mM glassy solutions of chromyl bis(1-hydroxy-cyclohexanecarboxylic acid), CrO(HCA)-2; aquo vanadyl ion, VO2+ (aq), and vanadyl bis(trifluoroacetylacetonate), VO(tfac)2 were examined. At low temperatures where 1/T1 << 1/Tm, 1/Tm in 1:1 H2O:glycerol is dominated by solvent protons. At low temperature 1/Tm increases in the order 1:1 H2O:glycerol or 9:1 CF3CH2OH:ethyleneglycol (no methyl groups) < 9:1 i-PrOH:MeOH (hindered methyl groups) < 9:1 n-PrOH:MeOH (less hindered methyl groups). This solvent dependence of 1/Tm is similar to that observed for nitroxyl radicals, which indicates that the effect of solvent methyl groups on spin-echo dephasing at low temperature is quite general. At higher temperatures the echo dephasing is dominated by spin-lattice relaxation and is concentration dependent. As the glass softens, echo dephasing is dominated by the onset of molecular tumbling.
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Affiliation(s)
- G R Eaton
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado, 80208,
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Lascola R, Wright JC. Measurement of the second-order molecular hyperpolarizability of fullerene anions by CARS spectroscopy. Chem Phys Lett 1998. [DOI: 10.1016/s0009-2614(98)00477-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Olsen SA, Bond AM, Compton RG, Lazarev G, Mahon PJ, Marken F, Raston CL, Tedesco V, Webster RD. EPR Studies Associated with the Electrochemical Reduction of C60 and Supramolecular Complexes of C60 in Toluene−Acetonitrile Solvent Mixtures. J Phys Chem A 1998. [DOI: 10.1021/jp972956a] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Scott A. Olsen
- Department of Chemistry, Monash University, Clayton, Victoria 3168, Australia, and Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Alan M. Bond
- Department of Chemistry, Monash University, Clayton, Victoria 3168, Australia, and Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Richard G. Compton
- Department of Chemistry, Monash University, Clayton, Victoria 3168, Australia, and Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Georgii Lazarev
- Department of Chemistry, Monash University, Clayton, Victoria 3168, Australia, and Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Peter J. Mahon
- Department of Chemistry, Monash University, Clayton, Victoria 3168, Australia, and Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Frank Marken
- Department of Chemistry, Monash University, Clayton, Victoria 3168, Australia, and Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Colin L. Raston
- Department of Chemistry, Monash University, Clayton, Victoria 3168, Australia, and Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Vanda Tedesco
- Department of Chemistry, Monash University, Clayton, Victoria 3168, Australia, and Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Richard D. Webster
- Department of Chemistry, Monash University, Clayton, Victoria 3168, Australia, and Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom
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Staško A, Brezová V, Rapta P, Biskupič S, Dinse KP, Gügel A. Anion radicals of [60]fullerenes. An EPR study. RESEARCH ON CHEMICAL INTERMEDIATES 1997. [DOI: 10.1163/156856797x00187] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Brezová V, Gügel A, Rapta P, Staško A. Electron Transfer to [60]Fullerene and Its o-Quinodimethane Adducts in Dimethyl Sulfoxide (EPR, Visible/Near-IR, and Electrochemical Study). ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp960547t] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Vlasta Brezová
- Faculty of Chemical Technology, Slovak Technical University, Radlinského 9, SK-812 37 Bratislava, Slovak Republic, and Max-Planck-Institut für Polymerforschung, Ackermannweg 10, D-55 128 Mainz, Germany
| | - Andreas Gügel
- Faculty of Chemical Technology, Slovak Technical University, Radlinského 9, SK-812 37 Bratislava, Slovak Republic, and Max-Planck-Institut für Polymerforschung, Ackermannweg 10, D-55 128 Mainz, Germany
| | - Peter Rapta
- Faculty of Chemical Technology, Slovak Technical University, Radlinského 9, SK-812 37 Bratislava, Slovak Republic, and Max-Planck-Institut für Polymerforschung, Ackermannweg 10, D-55 128 Mainz, Germany
| | - Andrej Staško
- Faculty of Chemical Technology, Slovak Technical University, Radlinského 9, SK-812 37 Bratislava, Slovak Republic, and Max-Planck-Institut für Polymerforschung, Ackermannweg 10, D-55 128 Mainz, Germany
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