Endohedral complexes of fullerene radical cations

Caldwell, Kenneth A.; Giblin, Daryl; Hsu, Chang Samuel; Cox, D. M.; Gross, Michael L.

doi:10.1021/ja00022a048

Cited by 144 publications

(48 citation statements)

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“…At these high energies the C6o cage will undoubtedly be unstable on the experimental gs time scale and is likely to undergo substantial fragmentation. One could, however, expect to see small signals corresponding to fragment ions containing a rare-gas atom, as has been reported for experiments with Ar atoms [3].…”

Section: Threshold Energies For Capturementioning

confidence: 61%

“…Collisions between rare gas atoms and C60 ions have been the most studied systems [2][3][4][5][6][7][8][9] at collision energies in the centre of mass of a few tens of electron volts, with complementary experiments in the same energy range but for rare gas ion -neutral C6o collisions [10]. Emphasis has been on measuring fragmentation patterns as a function of collision energy [2,3,[7][8][9][10] and on investigating the collisional formation of endohedral compounds Rg @ C6o with Rg = He or Ne [4][5][6][8][9][10][11]. More recently, ambitious experiments in which the dynamics of cluster-cluster collisions will be probed using C + + C6o as a model system have begun [9,12].…”

Section: Introductionmentioning

confidence: 99%

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Collisional dynamics of C60 with noble-gas-atoms studied by molecular dynamics with empirical two- and three-body forces

Ehlich

Campbell

Knospe

et al. 1993

Z Phys D - Atoms, Molecules and Clusters

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Abstract. The dynamics of C6o-rare gas collisions is studied using molecular dynamics with empirical two-and three-body forces. The carbon potential is chosen to be able to reproduce the experimentally determined bond lengths and cluster radius of C6o as well as the structure of small carbon clusters. The reaction channels observed can be divided into four categories: deep inelastic scattering, fragmentation, capture and inelastic scattering. The temperature dependence of the threshold energy for capture is studied and compared with available experimental data. The calculations predict a maximum in the lowest tail of the kinetic-energy distribution of the projectile with a transition from a single-to a double-humped maximum with increasing collision energy and, in addition, may provide a natural interpretation for the, as yet unexplained, structure in the experimental shapes.

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Section: Threshold Energies For Capturementioning

confidence: 61%

Section: Introductionmentioning

confidence: 99%

Collisional dynamics of C60 with noble-gas-atoms studied by molecular dynamics with empirical two- and three-body forces

Ehlich

Campbell

Knospe

et al. 1993

Z Phys D - Atoms, Molecules and Clusters

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“…In some cases more than one He atom was implanted into a fullerene. Caldwell et al (1991Caldwell et al ( , 1992 did similar experiments using He, Ne and Ar and found end products C 60He', C6oHe2, C7QHe', C84He`, CSS Ne` and CS,Ar'. Xe and Kr were not captured due to their larger size as compared to the space inside fullerenes.…”

Section: Trapping Of Free Oxygen and Hydroxyl Ions In Seed Particlesmentioning

confidence: 91%

“…This trapping will occur deeper in the atmosphere as the 0' incident energy increases (i.e., ion penetration into atmosphere increases as the ion initital energy increases). In case of Argon center of mass energies used were -450 eV, while for Kr center of mass energies were -1230 eV (Caldwell et al, 1991(Caldwell et al, , 1992. The higher center of mass energies can cause fragmentation of the fullerene with ejection of carbon atoms.…”

Section: Trapping Of Free Oxygen and Hydroxyl Ions In Seed Particlesmentioning

confidence: 99%

Heavy ion formation in Titan's ionosphere: Magnetospheric introduction of free oxygen and a source of Titan's aerosols?

Sittler

Ali

Cooper

et al. 2009

Planetary and Space Science

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“…Weiske et al [9] observed helium within the fragments of C 60 ϩ following high-energy collisions between the cations and the noble gas. Shortly after, the full He@C 60 ϩ adduct was observed [10,11]. Endohedral neon and argon compounds have also been produced by that method [12][13][14].…”

Section: ϫ and 4 He@c 60mentioning

confidence: 99%

Direct detection and quantitation of He@C₆₀ by ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry

Cooper

Hendrickson

Marshall

et al. 2002

J. Am. Soc. Mass Spectrom.

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In this paper, we report negative ion microelectrospray Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometry of C 60 samples containing ϳ1% 3 He@C 60 or 4 He@C 60 . Resolving 3 He@C 60 Ϫ and 4 He@C 60 Ϫ from C 60 containing 3 or 4 13 C instead of 12 C atoms is technically challenging, because the target species are present in low relative abundance and are very close in mass. Nevertheless, we achieve baseline resolution of 3 He@C 60 Ϫ from 13 C 3 12 C 57 Ϫ and 4 He@C 60 Ϫ from 13 C 4 12 C 56 Ϫ in single-scan mass spectra obtained in broadband mode without preisolation of the ions of interest. The results constitute the first direct mass spectrometric observation of endohedral helium in a fullerene sample at this (low) level of incorporation. The results also demonstrate the feasibility of determining the extent of He incorporation from the FT-ICR mass spectral peak heights. The present measurements are in agreement with those obtained by the pyrolysis method [1][2][3]. Although limited in sensitivity, the mass spectral method is faster and easier than pyrolysis. [4]) were observed [5,6] soon after the discovery of buckminsterfullerene (C 60 ) [7]. Following the development of the Krätschmer-Huffman method for preparation of fullerenes [8] (an electrical discharge between graphite electrodes in the presence of 0.2 atm of He gas), Smalley and co-workers produced macroscopic quantities of endohedral metallofullerenes in laser vaporization experiments on graphite doped with metal salts [4]. Weiske et al. [9] observed helium within the fragments of C 60 ϩ following high-energy collisions between the cations and the noble gas. Shortly after, the full He@C 60 ϩ adduct was observed [10,11]. Endohedral neon and argon compounds have also been produced by that method [12][13][14]. Another technique for the preparation of endohedral fullerene compounds is that of ion implantation (the endohedral species is neutralized on implantation). Endohedral species containing lithium and other alkali metals [15][16][17], the noble gases, He and Ne [18], and nitrogen [19] have been produced by that method.Endohedral compounds of all the noble gases can be prepared by heating fullerenes under high noble gas pressure [1][2][3]20]. Initially, yields of incorporation were approximately 0.1% for He, Ne, Ar and Kr and 0.03% for Xe. Subsequent experiments showed that reiterations of the labeling procedure resulted in higher yields of incorporation (ϳ1%) [21]. 3 He@C 60 , an NMR-active molecule, has also been prepared by that method [21,22]. Recent results have shown that the presence of KCN catalyzes the incorporation of noble gas, giving higher yields of incorporation (ϳ1%) in a single labeling experiment [23]. It is also known that He is trapped inside fullerenes (at about 1 ppm of empty fullerene) prepared by the Krätschmer-Huffman procedure [1,8]. In a recent finding, it was shown that fullerenes extracted from the Allende and Murchison meteorites contained endohedral helium [24]. The 3 He/ 4 He ratio in those fullerenes ...

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Endohedral complexes of fullerene radical cations

Cited by 144 publications

References 2 publications

Collisional dynamics of C60 with noble-gas-atoms studied by molecular dynamics with empirical two- and three-body forces

Collisional dynamics of C60 with noble-gas-atoms studied by molecular dynamics with empirical two- and three-body forces

Heavy ion formation in Titan's ionosphere: Magnetospheric introduction of free oxygen and a source of Titan's aerosols?

Direct detection and quantitation of He@C₆₀ by ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry

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Endohedral complexes of fullerene radical cations

Cited by 144 publications

References 2 publications

Collisional dynamics of C60 with noble-gas-atoms studied by molecular dynamics with empirical two- and three-body forces

Collisional dynamics of C60 with noble-gas-atoms studied by molecular dynamics with empirical two- and three-body forces

Heavy ion formation in Titan's ionosphere: Magnetospheric introduction of free oxygen and a source of Titan's aerosols?

Direct detection and quantitation of He@C60 by ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry

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Direct detection and quantitation of He@C₆₀ by ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry