MOLYBDENUM-CARBON BOND-DISSOCIATION ENERGIES IN MO(CO)6

The pressure dependence of the recombination rate constants for Mo(CO)n(n = 3, 4, and 5) with CO has been studied by time-resolved infrared laser absorption spectroscopy. These data, in conjunction with an RRKM model for unimolecular decay of the activated molecules [Mo(CO)6], [Mo(CO)5], and [Mo(CO)4], have allowed the determination of the bond dissociation energies for several of the Mo-C bonds in Mo(CO)6. The first Mo-C bond dissociation energies for Mo(CO)6, Mo(CO)5, and Mo(CO)4 are found to be DH°[(CO)5Mo···CO] = 35 ± 5 kcal/mol, DH°[(CO)4Mo···O] = 27 ± 5 kcal/mol, and DH°[(CO)3Mo···CO] = 31 ± 5 kcal/mol. © 1990 American Chemical Society.