Structure and Unprecedented Reactivity of a Mononuclear Nonheme Cobalt(III)-Iodosylbenzene Complex.

: A mononuclear nonheme cobalt(III)-iodosylbenzene complex, [Co(III)(TQA)(OH)(OIPh)]2+ (1), is synthesized and characterized structurally and spectroscopically. While 1 is a sluggish oxidant in oxidation reactions, it becomes a competent oxidant in oxygen atom transfer reactions, such as olefin epoxidation, in the presence of a small amount of proton. More interestingly, 1 shows a nucleophilic reactivity in aldehyde deformylation reaction, demonstrating that 1 possesses an amphoteric reactivity. Another interesting observation is that 1 can be used as an oxygen atom donor in the generation of high-valent metal-oxo complexes. To the best of our knowledge, the present study reports the first crystal structure of a Co(III)-iodosylbenzene complex and the unprecedented reactivities of metal-iodosylarene complexes, such as the nucleophilic reactivity in the deformylation of aldehydes and the use of a metal-iodosylbenzene complex as an oxygen atom donor in the synthesis of a metal-oxo complex.