A prototype for catalyzed amide bond cleavage: production of the [NH(3), H(2)O](*)(+) dimer from ionized formamide and its carbene isomer.

The reaction of ionized formamide H(2)NCHO(*)(+) with water leads to an exclusive loss of CO from the complex. This contrasts with the unimolecular reaction of low-energy ionized formamide, which loses exclusively one hydrogen atom. The unimolecular loss of CO is not observed because it involves several H-transfers corresponding to high-energy barriers.