CO Insertion Reactions into the M−OH Bonds of Monomeric Nickel and Palladium Hydroxides. Reversible Decarbonylation of a Hydroxycarbonyl Palladium Complex

The monomeric hydroxides M{C 6 H 3 -2,6-(CH 2 P i Pr 2 ) 2 }(OH) (M = Ni, Pd) react with carbon monoxide, giving rise to the binuclear CO 2 complexes [M{C 6 H 3 -2,6-(CH 2 P i Pr 2 ) 2 }] 2 (μ-CO 2 -κ 2 C, O ) (M = Ni, Pd). The formation of the Pd derivative takes place via the mononuclear species Pd{C 6 H 3 -2,6-(CH 2 P i Pr 2 ) 2 }(COOH), which is stable under a CO atmosphere but reversibly loses CO and H 2 O on attempted isolation.