Mean enthalpy of disruption to valence state for homoleptic transition metal carbonyls. A reassessment

Abstract

Summary The data necessary for an estimation of Δ H * , the enthalpy of disruption of an M CO bond to products in their valence states, is reexamined in the light of the high energy factored force field model (for force constants), the results of SCF MO calculations of electron configuration and charge, and recent thermochemical experiments. It is shown that, for the metals Cr, Mn, Fe, Co and Ni, the value of Δ H * is effectively constant (365 ± 10 kJ mol −1 ). The consequences of this are discussed briefly. An attempt has been made to extend this treatment to carbonyls of the 4 d and 5 d metals.