title: All-Carbon Molecules: Evidence for the Generation of Cyclo[18]carbon from a Stable Organic Precursor.
abstract: The unambiguous structural characterization of a single-sized all-carbon molecule requires its chemical synthesis. For cyclo[18]carbon, ab initio calculations predict a relatively stable, cyclic D9h ground state geometry with alternating C-C (1.36 angstroms) and C identical withC (1.20 angstroms) bonds. The synthesis and x-ray crystal structure of a direct precursor to C(18) are described. The analysis of laser flash heating experiments on this precursor by time-of-flight mass spectroscopy shows a sequence of retro-Diels-Alder reactions leading to C(18) as the predominant fragmentation pattern. Structural evidence is provided for the generation of an all-carbon molecule from a well-characterized organic precursor.
authors.forename: F
authors.initials: F
authors.lastname: Diederich
authors.forename: Y
authors.initials: Y
authors.lastname: Rubin
authors.forename: C B
authors.initials: CB
authors.lastname: Knobler
authors.forename: R L
authors.initials: RL
authors.lastname: Whetten
authors.forename: K E
authors.initials: KE
authors.lastname: Schriver
authors.forename: K N
authors.initials: KN
authors.lastname: Houk
authors.forename: Y
authors.initials: Y
authors.lastname: Li