SCO trimers as high-energy materials ? A density functional study

Density functional calculations using the hybrid B3LYP functional have been carried out on the fragmentation reaction of cyclic SCO trimers. Analogous calculations for CO2 and HNCO have also been performed for comparison. The energies of the different trimers relative to those of the isolated monomers as well as the energy barriers to fragmentation have been calculated. For all the calculations, a reaction path in which three bonds are simultaneously broken has been considered. It has been found that the fragmentation of cyclic SCO trimers is a rather facile process. The same statement applies to the cyclic CO2 trimer but not to the HNCO one. In addition, the latter is much more stable than three free HNCO monomers, which is not the case for SCO and CO2.