Synthesis of C120O: A new dimeric [60]fullerene derivative

Lebedkin, Sergei; Ballenweg, Stephan; Gross, Jürgen H.; Taylor, Roger; Krätschmer, Wolfgang

doi:10.1016/0040-4039(95)00784-a

Cited by 90 publications

(134 citation statements)

References 6 publications

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“…C 120O was prepared and HPLC-purified by literature methods. 17,19,20 Peak separation of C60 from C120O was 12 min, monitored at 330 nm. Concentrations were chosen such that baseline separation was typically ca.…”

Section: Methodsmentioning

confidence: 99%

“…The formation of C 120 O via reaction of the epoxide with free C 60 (eq 3) is a well-known reaction. 19 After the exposure of HPLC-purified C 60 to O 2 was terminated by placing the sample under vacuum, the EPR intensity continuously decreased to near baseline over 5 months. An HPLC analysis of the sample revealed C 120 O as a single major impurity in the C 60 sample.…”

Section: Does the Epr Signal In C 60 Arise From C 60mentioning

confidence: 99%

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Artifacts in the Electron Paramagnetic Resonance Spectra of C₆₀ Fullerene Ions: Inevitable C₁₂₀O Impurity

et al. 2002

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Aspects of the electron paramagnetic resonance (EPR) spectra of C60 n-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 C 120O n-(n ) odd). Signals arising from axial triplets (g ∼ 2.0015, D ) 26-29 G) in the spectrum of C60 2-are ascribed to C120O n-(n ) 2 or 4). Their D values are more realistic for C120O than C60. Less distinct signals from "powder" triplets (D ∼ 11 G) are ascribed to aggregates of C120O n-(n ) odd) arising from freezing nonglassing solvents. In highly purified samples of C60, we find no evidence for a broad ∼30 G signal previously assigned to a thermally accessible triplet of C60 2-. The C60 2-ion is EPRsilent. Signals previously ascribed to a quartet state of the C60 3-ion are ascribed to C120O 4-. 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 ∼ 2.0025, ∆Hpp ∼ 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 (∆Hpp ) 6-8 G). It is suggested that the EPR signal in airexposed 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.The addition of electrons to C 60 is its most characteristic chemical property. As a consequence, over the past decade, a great deal of effort has been put into characterizing the electronic structure of fulleride anions, C 60 n-. 1 In this paper, we show that the electron paramagnetic resonance (EPR) characterization of these ions has been significantly compromised by imprecise levels of reduction and by the presence of an unrecognized impurity in [60]-fullerene, namely, C 120 O.In addition, we question the widely held belief that the EPR signal commonly observed in solid "pristine" C 60 is due to the radical cation C 60•+ . [2][3][4][5][6] In contrast to the easy addition of electrons, the removal of electrons from C 60 is extremely difficult. 7 Thus, the formation of air-stable C 60 •+ radical cation centers is not easy to chemically rationalize. Now that a synthetic route to C 60•+ has become available, 8 a purposeful doping experiment into C 60 can be performed.The C 60 3-ion is a particularly important fulleride ion to characterize well because it gives rise to superconductivity in A 3 C 60 fulleride phases (A ) alkali metal). The triply degenerate nature of the t 1u lowest unoccupied molecular or...

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Section: Methodsmentioning

confidence: 99%

Section: Does the Epr Signal In C 60 Arise From C 60mentioning

confidence: 99%

Artifacts in the Electron Paramagnetic Resonance Spectra of C₆₀ Fullerene Ions: Inevitable C₁₂₀O Impurity

et al. 2002

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“…The synthesis of the oxygen-bridged dimer, C 120 -O, by reaction of the fullerene epoxide C 60 O with C 60 [37,38,39] provides, if the unfunctionalised C 60 is present in a large excess, a route to selective dimerisation. We have recently prepared the epoxide functionalised endohedral fullerene N@C 60 O [40], which holds potential for dimerisation with 15 N@C 60 to yield a 14 N-15 N two-qubit system.…”

Section: Fullerene Dimersmentioning

confidence: 99%

Towards a fullerene-based quantum computer

Benjamin

Ardavan

Briggs

et al. 2006

J. Phys.: Condens. Matter

177

141

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Abstract. Molecular structures appear to be natural candidates for a quantum technology: individual atoms can support quantum superpositions for long periods, and such atoms can in principle be embedded in a permanent molecular scaffolding to form an array. This would be true nanotechnology, with dimensions of order of a nanometre. However, the challenges of realising such a vision are immense. One must identify a suitable elementary unit and demonstrate its merits for qubit storage and manipulation, including input / output. These units must then be formed into large arrays corresponding to an functional quantum architecture, including a mechanism for gate operations. Here we report our efforts, both experimental and theoretical, to create such a technology based on endohedral fullerenes or 'buckyballs'. We describe our successes with respect to these criteria, along with the obstacles we are currently facing and the questions that remain to be addressed.

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“…12 In recent years, more attention has been paid to fullerene dimers because their unique physical and chemical properties provide intriguing possibilities as model compounds for nano-and polymer science, and offer potential access to novel molecular electronic devices. 13,14 In this respect, a series of fullerene dimers have been produced, such as C 120 , 15 the carbon-bridged dimers: C 121 , [16][17][18][19] C 140 , C 131 , 20 and C 122 , 15,19,21 and the heteroatom bridged dimer: C 120 O, [22][23][24] which could be used as the basic units of fullerene chain structures. The simplest fullerene dimer C 120 , (C 60 ) 2 , has been prepared by solid-state 25 and by chemical methods.…”

Section: -11mentioning

confidence: 99%

Fullerene Dimers Connected through C₂₄and C₃₆Bridge Cages

Anafcheh¹,

Ghafouri²

2014

Bulletin of the Korean Chemical Society

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We have performed DFT calculations to devise some possible fullerene dimers (from C60 and C80) connected through C24 and C36 bridge cages with the face-to-face linking model. The fullerene dimers with C36 bridges have lower binding energies and greater HOMO-LUMO gaps than those of the fullerene dimers with C24 bridges. Also, the replacement of C60 cages with C80 ones always leads to an increase in binding energies and HOMO-LUMO gaps in these systems. Dimerization of C60 and C80 fullerenes with C24 and C36 results in a significant decrease in antiaromaticity of the antiaromatic cages C24 and C80, and an increase in the aromaticity of the aromatic cages C36 and C60. Therefore, DFT results indicate that those fullerene dimers involving the initially harshly antiaromatic C24 or C80 cages are more energetically favorable configuration than the fullerene dimers involving the aromatic C36 and C60 cages.

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Synthesis of C120O: A new dimeric [60]fullerene derivative

Cited by 90 publications

References 6 publications

Artifacts in the Electron Paramagnetic Resonance Spectra of C₆₀ Fullerene Ions: Inevitable C₁₂₀O Impurity

Artifacts in the Electron Paramagnetic Resonance Spectra of C₆₀ Fullerene Ions: Inevitable C₁₂₀O Impurity

Towards a fullerene-based quantum computer

Fullerene Dimers Connected through C₂₄and C₃₆Bridge Cages

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Synthesis of C120O: A new dimeric [60]fullerene derivative

Cited by 90 publications

References 6 publications

Artifacts in the Electron Paramagnetic Resonance Spectra of C60 Fullerene Ions: Inevitable C120O Impurity

Artifacts in the Electron Paramagnetic Resonance Spectra of C60 Fullerene Ions: Inevitable C120O Impurity

Towards a fullerene-based quantum computer

Fullerene Dimers Connected through C24and C36Bridge Cages

Contact Info

Product

Resources

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Artifacts in the Electron Paramagnetic Resonance Spectra of C₆₀ Fullerene Ions: Inevitable C₁₂₀O Impurity

Artifacts in the Electron Paramagnetic Resonance Spectra of C₆₀ Fullerene Ions: Inevitable C₁₂₀O Impurity

Fullerene Dimers Connected through C₂₄and C₃₆Bridge Cages