Activation of SO 2 by N/Si + and N/B Frustrated Lewis Pairs: Experimental and Theoretical Comparison with CO 2 Activation

The guanidine 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene (TBD) and the substituted derivatives [TBD–SiR 2 ] + and TBD–BR 2 reacted with SO 2 to give different FLP–SO 2 adducts. Molecular structures, elucidated by X‐ray diffraction, showed some structural similarities with the analogous CO 2 adducts. Thermodynamic stabilities were both experimentally evidenced and computed through DFT calculations. The underlying parameters governing the relative stabilities of the different SO 2 and CO 2 adducts were discussed from a theoretical standpoint, with a focus on the influence of the Lewis acidic moiety.