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Reactions of Dioxygen Complexes of Nickel and Palladium Sei Otsuka,* A. Nakamura, Y. Tatsuno, and M. Miki Contribution ,from the Department of Chemistry, Faculty of Engineering Science, Osaka University, Toyonaka, Osaka, Japan, Received September 13, 1971 Abstract: The reactions of dioxygen complexes M02(t-BuNC)2(M = Ni, Pd) with a variety of reagents including CO, CO,, NO, N204,SOp,C6H5N0,RCOX, Ph3CBF4,etc., have been investigated. In each case metal complexes and organic substances produced were isolated and characterized to show several types of reactions, Le., (1) atomtransfer redox reactions, ( 2 ) atom-transfer oxidation reactions, (3) oxidative substitution reactions, and (4) metalassisted peroxidation reactions. The 0-0 bond is cleaved in reactions 1 and 2 while the bond is retained in reactions 3 and 4. Reactions of related complexes with molecular oxygen were also investigated. These results are
interpreted in terms of the electronic properties of coordinated dioxygen and reactants.
D
ioxygen complexes of low valent transition metals such as iridium,' rhodium, 2 , 3 platinum or ruthenium6 have been known for several years. The nature of dioxygen-metal bonding in these complexes of "soft" metals has been a subject of a number of recent However, studies on their reactivities bearing on the bonding nature are rather sparse, most of the studies being devoted to the reactions of a platinum phosphine complex, Pt(OS)(PPh&, with such molecules as CO," C02,11(13(18NO,'^ ~ 0 ~ , 1 4 ' 1 5 S02,15-17CS2,18 acetone,19120and other ketones.20,21 In addition to these stoichiometric reactions, the catalytic oxidations of t r i a r y l p h o s p h i n e ~ ~or, ~ alkylisocyanides2* with platinum, palladium, or nickel complexes have been examined. The available data, most of which are of preliminary accounts, appear not to fully cover their reactivities, and the scattered information does not allow us t o derive a consistent account of the chemistry. Previously we reported a few reactions of M(02)(t-BuNC), (M = Ni, P d ; t-Bu = tert(1) (a) L. Vaska, Science, 140, 809 (1963); (b) L. Vaska and D. L. Catone, J . Amer. Chem. Soc., 88,5324 (1966). (2) (a) J. T. Mague and G. Wilkinson, J . Chem. SOC.A , 1736 (1966); (b) M. C. Baird, D. N. Lawson, J. T. Mague, J. A. Osborn, and G. Wilkinson, Chem. Commun., 129 (1966). (3) I
