The Reaction of Cobaloximes with Hydrogen: Products and Thermodynamics

A cobalt hydride has been proposed as an intermediate in many reactions of the Co­(dmgBF₂)₂L₂ system, but its observation has proven difficult. We have observed the UV–vis spectra of Co­(dmgBF₂)₂L₂ (1) in CH₃CN under hydrogen pressures of up to 70 atm. A Co­(I) compound (6a) with an exchangeable proton is eventually formed. We have determined the bond dissociation free energy and pK_a of the new O–H bond in 6a to be 50.5 kcal/mol and 13.4, respectively, in CH₃CN, matching previous reports.