Ligand-Dominated Activation of CO₂ and CS₂ by the Putative Nickel Phosphiniminato Intermediates

Room-temperature photoactivation of the first- and second-generation PN³P-pincer nickel azido complexes 1a and 1b in the presence of CO₂ or CS₂ afforded N-bound carbamates, dithiocarbamates, and isothiocyanates, providing insights into CO₂ and CS₂ activation and demonstrating how a seemingly small difference in the ligand structure significantly influences the reactivity. Theoretical calculations disclosed that the charge of the phosphorus atom plays a critical role in determining the nitrogen atom transfer to form a plausible nickel phosphiniminato intermediate.