Do small fullerenes exist only on the computer? Experimental results on C=/−20 and C+/−24

Helden, Gert von; Hsu, Ming‐Teh; Gotts, Nigel G.; Kemper, Paul R.; Bowers, Michael T.

doi:10.1016/0009-2614(93)85599-j

Cited by 149 publications

(46 citation statements)

References 24 publications

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“…It is complementary to the study of O'Brien et al [26] and yon Helden et al [20][21][22]. Possible explanations for the differences between the latter two studies which show a clear cut-off at C32 and studies which do not exhibit such a cut-off-such as those of i) Cox et al [27], ii) Guo et al [28]; iii) Rohlfing [29]; Doverstal et al [35] as well as v) the present work, appear to be due to differences in the methods of cluster production as discussed in the discussion section.…”

Section: Introductionmentioning

confidence: 93%

“…The even species, on the other hand, show a fairly continuous smoothly varying overall contour pattern across the range n = 10-30. Recent studies by yon Helden et al [20][21][22] have shed some very important further light on the problem and shown that there are several families in the range. In particular they obtain results consistent those of O"Brien et al [26] who found that fullerenes with less than 32 atoms were not formed on successive fragmentation.…”

Section: Introductionmentioning

confidence: 98%

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Reaction studies of carbon clusters

Hallett

McKay

Balm

et al. 1995

Z Phys D - Atoms, Molecules and Clusters

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Abstract. Reaction studies of carbon clusters C, in the range n = 8-37, produced by laser vaporisation in a supersonic nozzle, have been investigated using time-offlight mass spectrometry. Clear differences in reaction products formed on hydrogenation are detected which show that even and odd clusters behave quite differently and furthermore that at least two different types of even cluster appear to exist. The reactivity patterns for clusters C, with n = t6, 18 and 22 are in a different class from those with n = 20, 24, 26 .... a behaviour consistent with the existence of closed cage fullerene structures for even clusters with 20 or more carbon atoms (other than n = 22).

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Section: Introductionmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 98%

Reaction studies of carbon clusters

Hallett

McKay

Balm

et al. 1995

Z Phys D - Atoms, Molecules and Clusters

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show abstract

“…However, there is experimental evidence showing that the dominant structure of C 20 is a monocyclic ring and a bicyclic ring. 9,10 Recently Prinzbach et al 11 provided experimental evidence for the existence of three different isomers: cage, bowl, and ring (see Fig. 1).…”

Section: Introductionmentioning

confidence: 99%

Uptake Effects of Two Electrons for Relative Stability and Atomic Structures of Carbon Cluster Isomers of C₂₀: ab initio Methods

Lee¹,

Lee²,

Kang³

et al. 2009

Bulletin of the Korean Chemical Society

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This study examined the effect of the uptake of one and two electrons on the atomic structure of three isomers of C20 clusters, namely the ring, bowl (corannulene like), and cage (the smallest fullerene). Geometry optimizations were performed using the hybrid density functional (B3LYP) methods for neutral, singly and doubly charged C20, C20 -, and C20 2-. These results show that the symmetry of the lowest energies for ring and bowl isomers were not changed, whereas the increasing order of energy for the cage (the smallest fullerene) isomers was changed from D2h < C2h ≤ C2 of C20 through Ci < C2h < C2 < D2h of C20 -to Ci < C2 < D2h < C2h of C20 2-. The reduced symmetry isomers of the cage have comparative energy and the ground state symmetry of the neutral and single and double charged C20 decreased with increasing number of electrons taken up in the point of energetics. Interestingly, the difference in energy between the ground state and the next higher energy state of C20 2-was 3.5kcal/mol, which is the largest energy gap of the neutral, single anion and double anion of the cage isomers examined.Key Words: C 20 cluster isomers, Electron uptake effects, Atomic structures, Hybrid density functional (B3LYP) calculations BowlCage Ring Figure 1. Three classes of structures of C20 cluster isomers (Bowl, cage, and ring). Here a, b, c, and the numbers in bowl and cage isomers represent the specific atomic site, but ns and nt in ring the nominal single and triple bonds.

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“…Although C 20 is the smallest possible fullerene, experimental evidences indicate that the dominant structures of C20 are monocyclic and bicyclic rings. 9,10 Recently, Prinzbach et al 11,12 provided experimental evidence for the existence of three different isomers: cage, bowl, and ring isomers (see Figure 1). Vibration spectra of these three isomers differ significantly from each other.…”

Section: Introductionmentioning

confidence: 99%

Full Geometry Optimizations of Bond-Stretch Isomers of C₂₀²⁺Fullerene Dication by the Hybrid Density Functional B3LYP Methods

Lee¹,

Lee²,

Park³

et al. 2011

Bulletin of the Korean Chemical Society

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We studied the relative stability and atomic structure of five C20 2+ isomers obtained by two-electron ionization of a C20 cage (the smallest fullerene). All the isomers are bond-stretch isomers, i.e., they differ in bond length. In particular, in one of the isomers with Ih symmetry, all the bond lengths are equal. Full geometry optimizations of the dipositive ion C20 2+ were performed using the hybrid density functional (B3LYP/6-31G(d)) methods. All isomers were found to be true minima by frequency analysis at the level of B3LYP/6-31G(d) under the reinforced tight convergence criterion and a pruned (99,590) grid. The zero-point correction energy for the cage bond-stretch isomers was in the increasing order D2h < C2h < C2 < Th < Ih of C20 2+ . The energy difference among the isomers of cage dipositive ions was less than that among neutral cage isomers. Our results suggest that these isomers show bond-stretch isomerism and that they have an identical spin state and an identical potential energy curve. Although the predominant electronic configurations of the isomers are similar, the frontier orbital characteristics are different, implying that we could anticipate an entirely different set of characteristic chemical reactions for each type of HOMO and LUMO.

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Do small fullerenes exist only on the computer? Experimental results on C=/−20 and C+/−24

Cited by 149 publications

References 24 publications

Reaction studies of carbon clusters

Reaction studies of carbon clusters

Uptake Effects of Two Electrons for Relative Stability and Atomic Structures of Carbon Cluster Isomers of C₂₀: ab initio Methods

Full Geometry Optimizations of Bond-Stretch Isomers of C₂₀²⁺Fullerene Dication by the Hybrid Density Functional B3LYP Methods

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Do small fullerenes exist only on the computer? Experimental results on C=/−20 and C+/−24

Cited by 149 publications

References 24 publications

Reaction studies of carbon clusters

Reaction studies of carbon clusters

Uptake Effects of Two Electrons for Relative Stability and Atomic Structures of Carbon Cluster Isomers of C20: ab initio Methods

Full Geometry Optimizations of Bond-Stretch Isomers of C202+Fullerene Dication by the Hybrid Density Functional B3LYP Methods

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Uptake Effects of Two Electrons for Relative Stability and Atomic Structures of Carbon Cluster Isomers of C₂₀: ab initio Methods

Full Geometry Optimizations of Bond-Stretch Isomers of C₂₀²⁺Fullerene Dication by the Hybrid Density Functional B3LYP Methods