SYNTHESIS AND REACTIVITY OF GEOMETRICALLY CONSTRAINED PHOSPHENIUM CATIONS

Both geometrically constrained phosphines (1) and phospheniums cations (2) activate various small molecules such as NH₃, H₂O, and ROH. However, up to date, both classes of these intriguing species were unable to activate molecules like H₂, CO, CO₂ etc.. The growing interest in activation of these small molecules due to their availability and synthetic potential motivated us to design reactive P-based compounds capable of activating these small molecules and transform them to value-added products. To design the desired P-based reactive compounds we combined both geometrically constrained phosphines and phosphenium cations approaches, to synthesize geometrically constrained phosphenium cations (3). Based on preliminary DFT calculations at WB97XD/DEF2TZV level of theory, compounds of type 3 should activate molecules like H₂, CO₂, etc., in a reversible manner. Herein, we present the progress in the synthesis of the desired 3 and theoretical predictions to their reactivity.