Sc3N@C80: Computations on the Two-Isomer Equilibrium at High Temperatures
✍ Scribed by Zdeněk Slanina ; Shigeru Nagase
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- English
- Weight
- 90 KB
- Volume
- 6
- Category
- Article
- ISSN
- 1439-4235
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Reported herein are computations on the relative concentrations of the two experimentally known isomers of Sc~3~N@C~80~ , that is, those produced by encapsulation of Sc~3~N in two particular C~80~ cages that obey the isolated‐pentagon rule, namely, with I~h~ and D~__5__h~ symmetries. The calculations are based on density functional methods and have been carried out using the Gibbs energy over a broad temperature interval. It has been computed that, if a relatively free motion of the encapsulate inside the cages is allowed, the observed populations of 10 and 17 % for the D~5__h~ Sc~3~N@C~80~ species are reached at temperatures of 2100 and 2450 K, respectively. The inclusion of the entropy term is essential as, if it is neglected, the D~5__h~ Sc~3~N@C~80~ population at a temperature of 2100 K would be a mere 1 %, owing to the relatively large interisomeric separation potential energy of 19 kcal mol^−1^.