Carbon clusters containing two metals atoms: Structures, growth mechanism, and fullerene formation

Journal Article · Wed Feb 07 04:00:00 EST 1996 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/ja953071k· OSTI ID:219650

Shelimov, K B; Jarrold, M F ^[1]

---

1. Northwestern Univ., Evanston, IL (United States)

Gas phase ion mobility measurments have been used to probe the structures and interconversion of La{sub 2}C{sub n}{sup +} (n = 1-100) isomers. The smallest La{sub 2}C{sub n}{sup +} clusters (n = 10) appear to be planar rings. However, planar mono and bicylic rings (the dominant isomers for C{sub n}{sup +} and LaC{sub n}{sup +}, n = 30, clusters) are not observed for the larger La{sub 2}C{sub n}{sup +} species. Instead, isomers which appear to be three-dimensional ring complexes dominate for unannealed La{sub 2}C{sub n}{sup +} (n + 17) clusters. The formation of these complexes is probably driven by electrostatic forces. For n = 30 the three-dimensional ring complexes isomerize into metallofullerenes (and metal-containing graphite sheets for n = 30-37). The estimated activation energies for these isomerization processes are about 1eV lower than those estimated for similar processes for planar C{sub n}{sup +} and LaC{sub n}{sup +} rings. Metallofullerenes with two non-endohedral metal atoms (for n = 28-29), one endohedral metal atom (for n = 31-100), and two endohedral metal atoms (for n > 64, only even n), are identified. Fullerene derivatives (presumably fullerene + ring complexes) are abundant in the unannealed isomer distributions for La{sub 2}C{sub n}{sup +} (n > 50) clusters, but readily isomerize into regular fullerenes upon collisional heating. 47 refs., 9 figs., 2 tabs.

• OSTI ID: 219650
• Journal Information: Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 5 Vol. 118; ISSN JACSAT; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
ACTIVATION ENERGY
CARBON
DISSOCIATION
FULLERENES
ION MOBILITY
ISOMERIZATION
ISOMERS
LANTHANUM COMPLEXES
SOLID CLUSTERS
STRUCTURAL CHEMICAL ANALYSIS