A Combined Experimental and Theoretical Study of the Versatile Reactivity of an Oxocerium(IV) Complex: Concerted Versus Reductive Addition.

A combined experimental and theoretical investigation on the cerium(IV) oxo complex [(L ) Ce(=O)(H O)]⋅MeC(O)NH (1; L =[Co(η -C H ){P(O)(OEt) } ] ) demonstrates that the intermediate spin-state nature of the ground state of the cerium complex is responsible for the versatility of its reactivity towards small molecules such as CO, CO , SO , and NO. CASSCF calculations together with magnetic susceptibility measurements indicate that the ground state of the cerium complex is of multiconfigurational character and comprised of 74 % of Ce and 26 % of Ce . The latter is found to be responsible for its reductive addition behavior towards CO, SO , and NO. This is the first report to date on the influence of the multiconfigurational ground state on the reactivity of a metal-oxo complex.