Isolation of Two Seven-Membered Ring C58 Fullerene Derivatives: C58F17CF3 and C58F18
Pavel A. Troshin,1
Anthony G. Avent,2
Adam D. Darwish,2
Natalia Martsinovich,2
Ala'a K. Abdul-Sada,2
Joan M. Street,3
Roger Taylor2*
Fluorination of C
60 at 550°C leads to milligram quantities
of two stable fullerene derivatives with 58-carbon cage structures:
C
58F
18 and C
58F
17CF
3. The compounds were characterized by mass
spectrometry and fluorine nuclear magnetic resonance spectroscopy,
and the data support a heptagonal ring in the framework. The
resulting strain, which has hindered past attempts to prepare
these smaller quasi-fullerenes, is mitigated here by hybridization
change of some of the carbons in the pentagons from sp
2 to sp
3 because of fluorine addition. The loss of carbon from C
60 is
believed to occur via sequential fluorine addition to a C–C
single bond and an adjacent C
C bond, followed by loss of a :CF
2 carbene.
2 Chemistry Department, Sussex University, Brighton BN1 9QJ, UK.
3 School of Chemistry, University of Southampton, Southampton SO17 1BJ, UK.
* To whom correspondence should be addressed. E-mail: R.Taylor{at}sussex.ac.uk
