Solvent-Driven Reductive Activation of CO2 by Bismuth: Switching from Metalloformate Complexes to Oxalate Products.

In this work, we investigated how the reductive activation of CO2 with an atomic bismuth model catalyst changes under aprotic solvation. IR photodissociation spectroscopy of mass-selected [Bi(CO2 )n ]- cluster ions was used to follow the structural evolution of the core ion with increasing cluster size. We interpreted the IR spectra by comparison with density-functional-theory calculations. The results show that CO2 binds to a bismuth atom in the presence of an excess electron to form a metalloformate ion, BiCOO- . Solvation with additional CO2 molecules leads to the stabilization of a bismuth(I) oxalate complex and results in a core ion switch.