KINETICS AND MECHANISM OF SUBSTITUTION REACTIONS OF DINITROSYLDICARBONYLIRON(O)

Dinitrosyldicarbonyliron(0) undergoes carbon monoxide substitution reactions in the presence of phosphines, phosphites, and triphenylarsine to give the monosubstituted derivatives, Fe(NO)2(CO)L. The preparation and spectra of several mono- and disubstituted derivatives are reported. The rates of these reactions depend on the concentration and nature of reagent. For reagents with the same donor atom, the rates of reaction increase with increasing basicity (or polarizability) of the reagents. The results obtained support a bimolecular displacement mechanism with nucleophilic attack by the entering reagent on the class b or soft iron(0). This is discussed in terms of the nature of the chemical bonding in Fe(NO)2(CO)2. © 1968, American Chemical Society. All rights reserved.