https://doi.org/10.1140/epjd/e2013-30646-0
Regular Article
The role of the C2 gas in the emergence of C60 from the condensing carbon vapour
1
Government College University (GCU), CASP, Church Road, 54000
Lahore,
Pakistan
2
Pakistan Institute of Nuclear Science and Technology
(PINSTECH), P.O.
Nilore, Islamabad,
Pakistan
a
e-mail: sahmad.ncp@gmail.com
Received: 20 October 2012
Received in final form: 19 December 2012
Published online: 19 March 2013
A model has been developed that illustrates C60’s emergence from the condensing carbon vapour. It is shown to depend upon (i) the decreasing heats of formation for larger cages; (ii) exponentially increasing number of isomers for fullerenes that are larger than C60; (iii) large cages’ buckling induced by the pentagon-related protrusions that initiate fragmentation; (iv) the structural instability-induced fragmentation that shrinks large cages via Cx → Cx−2 + C2; and (v) an evolving gas of C2 that is crucial to the whole process. The model describes a mechanism for the provision and presence of plenty of C2s during the formation and fragmentation processes. Fullerenes portrayed as 3D rotors have partition functions describing ensemble’s entropy as a function of the fragmentation sequence. The bottom-up formations of large cages followed by the top-down cage shrinkage are shown to be stable, dynamical processes that lead to the C60 dominated fullerene ensemble.
Key words: Molecular Physics and Chemical Physics
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag 2013