[RhH] and [Rh][O2CH] Complexes as Models for the Catalytically Active Intermediates in the Rh‐Catalyzed Hydrogenation of CO2 to HCOOH

The insertion of CO2, into the RhH bond of neutral hydrido complexes to form ionic complexes of type 1 now appears to be the key step in the title reaction. All intermediates were either isolated or detected by spetroscopy. The influence of the phosphane ligands on the reactivity of these model complexes is the same as their influence on the activity of the in situ catalysts normally used.