Tetrel bond between X2TO (T= C, Si, Ge, Sn; X = H, F, Cl, Br, CH3) and CO2. An effective absorbent for CO2

Abstract

Quantum chemical calculations are applied to study the complexes between X2TO (X=H, F, Cl, Br, CH3; T=C, Si, Ge, Sn) and CO2. The carbon atom of CO2 as a Lewis acid participates in the O•••C carbon bond, whereas its oxygen atom as a base engages in the O•••T tetrel bond with X2TO. Most of complexes are stabilized by a combination of both O•••C and O•••T interactions. The interaction energies are dependent on the nature of T and X atoms/groups. Both the electron-withdrawing halogen group and the electron-donating methyl group increase the interaction energy, up to 51 kJ/mol in F2SiO•••CO2. One F2SiO molecule can bind with different number of CO2 molecules from one to four; as the number of CO2 increases, the average interaction energy for each CO2 is decreased but it can contribute at least 27 kJ/mol stabilization energy. Therefore, silicon-containing molecules are good absorbents for CO2.