The Pi-Hole Tetrel Bond Between X2to And Co2: Substituent Effects And Its Potential Adsorptivity For Co2

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 C center dot center dot center dot O carbon bond, whereas its oxygen atom as a base engages in the O center dot center dot center dot T tetrel bond with X2TO. Most of complexes are stabilized by a combination of both C center dot center dot center dot O and O center dot center dot center dot T interactions. The interaction energy increases in the T = C < Ge < Sn < Si sequence for most complexes. Both the electron-withdrawing halogen group and the electron-donating methyl group increase the interaction energy, up to 51 kJ/mol in F2SiO center dot center dot center dot CO2. One F2SiO molecule can bind with different numbers of CO2 molecules (1-4); as the number of CO2 molecules increases, the average interaction energy for each CO2 decreases and each CO2 molecule can contribute with at least 27 kJ/mol. Therefore, silicon-containing molecules are good absorbents for CO2.