Research Article

Computational Study on the Intramolecular Carbene-CO Coupling in M(CH2)(CO)3 Radicals (M = Co, Rh, Ir)

Table 2

Reaction Gibbs free energies and free energy barriers for the formation of coordinatively saturated ketene complexes via CO uptake (top 6 rows) and via the concerted mechanism (bottom 6 rows).

Reaction (kcal/mol) (kcal/mol)

3Co4Co (gas phase)−22.0
3Co4Co (CH2Cl2)−19.3
3Rh4Rh (gas phase)−15.8
3Rh4Rh (CH2Cl2)−12.5
3Ir4Ir (gas phase)−22.2
3Ir4Ir (CH2Cl2)−17.5
1Co6TSCo4Co (gas phase)−35.78.0
1Co6TSCo4Co (CH2Cl2)−37.57.9
1Rh6TSRh4Rh (gas phase)−24.99.0
1Rh6TSRh4Rh (CH2Cl2)−25.88.7
1Ir6TSIr4Ir (gas phase)−20.810.2
1Ir6TSIr4Ir (CH2Cl2)−21.410.1