Formation, structures, and reactivity of cis-hydroxy-, cis-methoxy-, and cis-mercaptoiridium hydrides. Oxidative addition of water to Ir(I)

Abstract

Although mononuclear hydrido hydroxy complexes may play an important role in water activation, including the water gas shift reaction, olefin and nitrile hydration, exchange reactions, and photodissociation of water, only few of them are known. The early-transition-metal complexes of this type tend to dimerize, whereas the late-transition-metal complexes tend to be unstable in the absence of excess water, probably because of an unfavorable formation constant. None of these complexes has been crystallographically characterized. They report here the isolation, properties, and crystallographic characterization, revealing some unusual features, of a stable, mononuclear hydrido hydroxy complex formed by facile water oxidative addition to Ir(I). A rare example of a mononuclear hydrido methoxy complex derived from it is also described. For comparison a hydrido mercapto complex is also presented.