Isolation of Au-, Co-η 1 PCO and Cu-η 2 PCO complexes, conversion of an Ir–η 1 PCO complex into a dimetalladiphosphene, and an interaction-free PCO anion

Sodium phosphaethynolate reacts with [MCl(PDI)] (M = Co, Ir; PDI = pyridinediimine) to give metallaphosphaketenes, which in the case of iridium rearranges into a dimetalladiphosphene.