Resilience of all-carbon molecules C sub 60 , C sub 70 , and C sub 84 : A surface-scattering time-of-flight investigation

Journal Article · Thu Oct 17 00:00:00 EDT 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100174a066· OSTI ID:7163625

Beck, R D; John, P; Alvarez, M M; Diederich, F; Whetten, R L ^[1]

---

1. Univ. of California, Los Angeles (United States)

Ion beam scattering experiments on the larger carbon molecules (C{sub 60}{sup {plus minus}}, C{sub 70}{sup +} C{sub 80}{sup +}) demonstrate their exceptionally high stability with respect to impact-induced fragmentation processes. The charged molecules are formed by ultraviolet laser desorption of high purity molecular samples into a pulsed helium jet. Extracted ions impact Si(100) or graphite (0001) in a high-resolution ion beam/surface collider with mass time-of-flight and angular analysis. Collisions are highly inelastic processes: a large fraction of the entire perpendicular momentum component is lost, and 60 {plus minus} 20% of the component is either lost or exchanged. No more than 10% of the incident ions are returned, which is attributed to neutralization during the collision event. In contrast to all molecular ions (benzene and naphthalene cations) and cluster (alkali-metal halides), these molecules exhibit no evidence for impact-induced fragmentation, even at impact energies exceeding 200 eV. In the case of C{sub 60}{sup {minus}}, both the intact parent ion and ejected electrons are detected, with the latter becoming dominant above 120 eV impact energy. C{sub 60}{sup +} is found to have an exceptionally low energy threshold for inducing sputtering processes of adsorbed overlayers on graphite. Some of these results may be interpretable in terms of the unique structural-energetic characteristics of the fullerene family. The results are compared to recent computer simulations of the impact event, which predict high resilience for these molecules.

• OSTI ID: 7163625
• Journal Information: Journal of Physical Chemistry; (United States), Vol. 95:21; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
FULLERENES
SCATTERING
ANGULAR DISTRIBUTION
CATIONS
COMPUTERIZED SIMULATION
DESORPTION
EXPERIMENTAL DATA
GRAPHITE
LASER RADIATION
MASS SPECTROSCOPY
MILLER INDICES
SILICON
STOICHIOMETRY
SURFACES
TIME-OF-FLIGHT MASS SPECTROMETERS
ULTRAVIOLET RADIATION
CARBON
CHARGED PARTICLES
DATA
DISTRIBUTION
DYNAMIC MASS SPECTROMETERS
ELECTROMAGNETIC RADIATION
ELEMENTAL MINERALS
ELEMENTS
INFORMATION
IONS
MASS SPECTROMETERS
MEASURING INSTRUMENTS
MINERALS
NONMETALS
NUMERICAL DATA
RADIATIONS
SEMIMETALS
SIMULATION
SORPTION
SPECTROMETERS
SPECTROSCOPY
TIME-OF-FLIGHT SPECTROMETERS
400201* - Chemical & Physicochemical Properties