Effect of the embedded atom on the electronic, optical properties and kinetic stability of [3,6]silaprismane

- Silaprismane Si18H12 is more kinetically stable than the C18H12 prismane.
- C, Si or Ge atom embedded inside the Si18H12 cage reduces its stability.
- Silaprismane Si18H12 conserves its identity for a few hours at room temperature.
- Endoprismanes based on Si18H12 cage can be separated through their optical spectra.

Using ab initio calculations it is found that endohedral complexes C@Si18H12, Si@Si18H12 and Ge@Si18H12 are less kinetically stable than pure [3,6]silaprismane Si18H12. Moreover, kinetic stability of Si18H12 is higher than the stability of its carbon molecular analogue C18H12. The height of the minimum energy barrier preventing the Si18H12 isomerization is found to be 1.09 eV and its lifetime at room temperature will reach several hours that is acceptable not only for its immediate experimental observation but for the laboratory synthesis without using the extreme temperature conditions as well. It is also found that embedded atoms can significantly change the electronic properties of Si18H12 cage that is directly affect the optical characteristics of the systems considered. Thus, the doped Si18H12s can be experimentally divided from each other due to the changes in their optical spectra.

Kinetic stability of pure Si18H12 is higher than the C18H12 stability, but guest atoms are able to decrease it strongly.73