Insertion of Carbon Dioxide into Main‐Group Complexes: Formation of the [N(CO₂)₃]³⁻ Ligand

Abstract

Under mild conditions CO2 reacts with [Sr{N(PPh2)2}2](THF)3 to oxidatively cleave PPh2 groups, resulting in the new ligand [N(CO2)3]3− in [Sr6{O2CN(PPh2)2}6{N(CO2)3}2] (see core structure; Sr green, O red, N blue, C black). The Sr6 framework chemically fixates twelve equivalents of CO2, half by the formation of two [N(CO2)3]3− ligands and the other half by CO2 insertion to form the unprecedented phosphanyl-substituted carbamate ligand O2CN(PPh2)2.