Are clusters of nonpolar molecules icosahedral?

Schriver, K. E.; Paguia, A. J.; Hahn, M. Y.; Honea, Eric C.; Camarena, A. M.; Whetten, Robert L.

doi:10.1021/j100296a006

Cited by 32 publications

(18 citation statements)

References 5 publications

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“…Schriver et al found that benzene cluster ions are particularly stable with respect to evaporative decay when they contain 14, 20, 24, or 27 molecules. 33 These numbers are each one greater than the corresponding magic numbers of rare-gas clusters. Therefore, they attributed the observed stability to icosahedral packing about a central dimer ion (charge-localized model).…”

Section: Resultsmentioning

confidence: 94%

Electronic Structures and Photoevaporation Dynamics of Benzene Cluster Ions

1997

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The electronic spectra of benzene cluster ions, (C 6 H 6 ) n + with n ) 3-6, are measured through mass-selected photodissociation spectroscopy. The spectra in the 400-1100-nm region show three distinct absorption maxima centered around 430, 590-620, and 950 nm, which are analogous to the spectrum of (C 6 H 6 ) 2 + . The 950-nm band is assigned to a charge resonance (CR) band characteristic of the dimer ion, while the other two bands are attributed to local excitation bands. The position of the CR band is found to be almost independent of cluster size. The result suggests that the cluster ions have a charge-localized structure involving a strongly bound dimer ion core. In addition, the number and translational energy of neutral molecules ejected following photoexcitation are measured for (C 6 H 6 ) n + with n ) 3-8 in the photon energy range of 0.5-3.0 eV. The average number of ejected molecules increases linearly with increasing photon energy, suggesting that the fragmentation proceeds via the sequential ejection of neutral monomers. The average translational energy carried by one monomer is determined to be 50-70 meV, which is comparable with the calculated value according to a statistical theory. A large part of the imparted photon energy is partitioned into internal energies of the products. These results indicate that the photofragmentation of (C 6 H 6 ) n + can be regarded as a unimolecular decay of vibrationally hot clusters, despite the promotion of the chromophoric dimer core to the repulsive excited state.

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Section: Resultsmentioning

confidence: 94%

Electronic Structures and Photoevaporation Dynamics of Benzene Cluster Ions

1997

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“…Reducing the reflection voltage to a critical value causes the parent ions to be transmitted entirely, so that the metastables can be more easily identified. This technique has been used to study ammonia [13] and benzene [14] clusters, as well as other systems of general interest.…”

Section: Methodsmentioning

confidence: 99%

Metastability of gold-carbonyl cluster complexes, Au N(CO) M-

Wallace

Whetten

2001

The European Physical Journal D

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Smaller gold-cluster anions, typified by Au − 7 , adsorb multiple CO molecules in a high-pressure, room-temperature flow-reactor, tending toward previously unknown saturation compositions, Au7(CO) − 4 . The weakness of the gold-carbonyl adsorption bond is evidenced indirectly by the high CO partial pressure required and more directly by the high probability of fragmentation in the field-free flight region of the reflectron-type time-of-flight mass spectrometer. The analysis of this metastability reveals that the actual distribution fN,M of products Au7(CO) − M in the reactor may be highly non-statistical, e.g. with only even-M species present.

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“…The calculated aggregation factors g are small, compared to the large clusters reported for instance in benzene vapor (aggregates of 14, 20, 24 appear to be particularly stable) [25]. At higher temperatures the calculated 9 decreases.…”

Section: Applications and Discussionmentioning

confidence: 64%

“…Clusters are produced in free-jet expansions [10,11] both from metals and molecular liquids. It is not their existence but the inner structure of these clusters that is under discussion.…”

Section: Introductionmentioning

confidence: 99%

Pure liquids described as concentrated cluster dispersions

Kunnen

1988

Rheol Acta

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Abstract:The Fulcher-Tammann-Hesse-Vogel equation, lnr/= A + B / ( T -T o ) , is shown to be equivalent to the general viscosity-composition relationship, In t/r = k f ~0/ (1 -fcp), for binary mixtures. The Cailletet-Mathias law of the Rectilinear Diameter is rearranged to represent a density mixture formula for two components. Temperature-independent viscosities and densities can then be calculated for dense, solid cluster fractions, dispersed in a low-density, low-viscosity non-clustered continuous phase. The cluster fraction decreases with temperature. The value of T o is shown to be related to the liquid-or solid-like behavior of the clusters. For liquids with a vapor pressure < 1 mm Hg at the melting point, the calculated cluster volume fraction suggests close packing of clusters, ranging in shape from monodisperse spheres to polydisperse non-spherical particles. Examples are given for molecular liquids, molten metals, and molten salts. The size of the clusters is estimated from the heat of evaporation.

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Are clusters of nonpolar molecules icosahedral?

Cited by 32 publications

References 5 publications

Electronic Structures and Photoevaporation Dynamics of Benzene Cluster Ions

Electronic Structures and Photoevaporation Dynamics of Benzene Cluster Ions

Metastability of gold-carbonyl cluster complexes, Au N(CO) M-

Pure liquids described as concentrated cluster dispersions

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