This study is related to reactivity of dioxygen bridged palladium complexes having ¥ð-allyl ligands. In this case, new dioxygen bridged palladium complexes were prepared using superoxide ion(O2-) as an oxygen source. Reactions of the dioxygen palladium complexes prepared in the study were examined in order to clarify the nature of the coordinated dioxygen. Treatments of a solution of the dioxygen bridged palladium complexes in benzene by water, methanol and acetic acid gave hydrogen peroxide (H2O2) as hydroxy-, methoxy-, and acetoxybridged palladium complexes, respectively. The dioxygen bridged palladium complexes reacted also with substitution phenols of salicylaldehyde, 8-hydroxyquinoline and active methylenes of acetylacetone, dimethyl malonate to afford mononuclear complexes of palladium and hydrogen peroxide. The results suggest that dioxygen is coordinated as peroxo (O22-) in the complexes and behaves as a strong base.
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