The reaction of [IrIII{C(dppm)2-κ3 P,C,P′}ClH(NH3C2)]Cl with ethyl diazo­acetate, a well known C=C coupling reagent, leads to the formation of a C=C unit, accompanied by N2 abstraction, and reorganization of a dppm subunit and, considered as a whole, to the transformation of the PCP pincer carbodi­phospho­rane system to a phospho­rus ylide ligand. After removal of the halogenides, the iridium center is stabilized by the carbonyl O atom through the formation of a five-membered chelate ring. A PCO pincer ligand system is thereby generated, which coordinates the iridium(III) atom threefold in a facial manner. The addition of carbon monoxide causes a replacement of the carbonyl O atom of the acetate subunit by a carbonyl ligand.

In this communication, two compounds and their respective crystal structures, obtained via fragmentation of the triazene moiety in a PCN pincer iridium complex, are discussed. One showcases a novel (dppm)C(N2dppm) PCP pincer, the other contains a (dppm)C(N2) diazo­methyl­ene­phospho­rane moiety.