The reaction of C 2H 5I with photogenerated Fe(CO) 4 was followed using time-resolved infrared spectroscopy. Three novel products were detected. On the basis of their carbonyl stretching frequencies, their kinetics, and calculations of their relative energies, these complexes are assigned as IFe(CO) 4(C 2H 5), IFe(CO) 3(η 2-COC 2H 5), and IFe(CO) 4(COC 2H 5). Addition of C 2H 5I to Fe(CO) 4 produces IFe(CO) 4(C 2H 5) as the kinetically preferred product, which then converts to IFe(CO) 3(η 2-COC 2H 5), the thermodynamically preferred complex. IFe(CO) 4(COC 2H 5) is formed upon addition of CO to IFe(CO) 3(η 1-COC 2H 5), a 16-electron complex that is proposed as a common intermediate leading to the three products. Temperature-dependent studies of the kinetics of the decay of IFe(CO) 4(COC 2H 5), the longest lived of the products, indicate that it decarbonylates with an activation energy of ∼20 kcal/mol.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry