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

Room-temperature photoactivation of the first- and second-generation (PNP)-P-3-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.