Surface organometallic chemistry: Formation of the grafted anionic clusters [HFeOs3(CO)13]-, [HFeRu3(CO)13]-, and [FeCo3(CO)12]- on a hydroxylated magnesia

Article abstract of DOI:10.1021/om00139a007

The reaction of the mixed hydrido carbonyl H₂FeM₃(CO)₁₃ (M = Ru, Os) and HFeCo₃(CO)₁₂ with the surface of partially hydroxylated magnesia has been studied in situ by IR spectroscopy, evolution of gases, and extraction of the adsorbed complexes. At room temperature, H₂FeM₃(CO)₁₃ (M = Ru, Os) and HFeCo₃(CO)₁₂ are deprotonated at the surface of magnesia to give the anions [HFeM₃(CO)₁₃]^- (M = Ru, Os) and [FeCo₃(CO)₁₂]^- with virtually no disproportionation to other cluster species. The anions [HFeM₃(CO)₁₃]^- (M = Ru, Os) were also synthesized by proton abstraction by KOH and by KH. It is suggested that on the surface of the magnesia the deprotonation occurs via surface OH groups. From IR spectra apparently there is no tight ion pair between the anions on the surface and the Lewis centers which is in contrast with that which is observed for [HFe₃(CO)₁₁]^- (M = Fe). A mechanistic explanation is proposed. Thermal decomposition of the surface-bound anions has been studied.