Metal ion-decorated hexasilaprismane and its derivative as a molecular container for the separation of CO 2 from flue gas molecules: a computational study.

The electronic structure of hexasilaprismane (HSP) was examined with different computational techniques to elucidate the bonding features and the electrostatic surface potential of HSP. The carbon dioxide adsorption and separation capacities of metal-ion-decorated hexasilaprismane (HSP) were examined with DFT and CBS-QB3. Furthermore, the 1,2,3,4,5,6-hexaphenylprismasilane (HPPS) molecule was examined for its binding with metal ions and gas adsorption capacity. The Mg 2+ ion complexed HPPS molecule adsorbs 15CO 2 molecules with an average binding free energy of -0.98 eV per molecule. The calculated gravimetric densities of 45.1 and 48.4 wt% show that these systems can be employed for CO 2 capture. The substantial difference in the affinity of the designed systems for CO 2 gas molecules compared to N 2 and CH 4 molecules show the potential of the systems for CO 2 separation from N 2 and CH 4 gas molecules.