Oxidative Addition of Water to Ir(I) Complexes Bearing a Pincer-Type Silyl Ligand

[Image: see text] Reaction of water with in situ generated [(PSiP-R)Ir(I)] (PSiP-R = [{2-(R(2)P)C(6)H(4)}(2)MeSi](−); R = cyclohexyl, tBu or iPr) from [(PSiP-R)Ir(H)(4)] and tert-butylethylene (tbe) showed high ligand dependency. Oxidative addition of water cleanly proceeded in the reaction of [(PSiP-tBu)Ir(I)] in THF at room temperature to selectively afford a 16-electron hydrido–hydroxo complex [(PSiP-(t)Bu)Ir(H)(OH)] almost quantitatively. In contrast, the reaction of cyclohexyl and iPr derivatives was unselective and formed various products containing Ir–H bonds. In the case of iPr-derivative, a small amount of 18-electron hydrido–hydroxo aqua complex [(PSiP-iPr)Ir(H)(OH)(H(2)O)] was isolated and structurally characterized by X-ray crystallography.