Abstract Reaction of pentacarbonyl iron(O) with 1,2-quinone mono-oximes (qoH) gives the Fe(qO)2 complexes as the main products together with various organic products. In the presence of aniline the main products are again the complexes Fe(qO)2 which are accompanied by the formation of organic products and complexes of type Fe(qo-A)2 where qo-A is a species arising from the coupling of the qo ligand with aniline. The formation of the latter type of complex and of the organic products is rationalized in terms of deoxygenation of the qo ligand. The complexes Fe(qo)2 and Fe(qo-A)2 have oligomeric structures as indicated by their magnetic properties and Mössbauer spectra. Both these types of complex react with pyridine to give dipyridine adducts.