Field ionisation/field desorption mass spectrometry of polynuclear metal carbonyls

Field ionisation/field desorption mass spectra are reported for Mn2(CO)10, Cd[Co(CO)4]2 and some adducts, In[Co(CO)4]3, bipy•Zn[Co(CO)4]2, and bipy•M[Mn(CO)5]2 (M = Zn, Cd). The spectra are extremely simple, and the small number of easily identified species includes the molecular ion in some cases. The relative abundance of the fragments is discussed in terms of known stabilising factors in such compounds. No spectra could be obtained from Co2(CO)8 or Fe2(CO)9, which may be the result of their carbonyl-bridged structures.