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

Reaction of water
with in situ generated [(PSiP-R)­IrI] (PSiP-R = [{2-(R2P)­C6H4}2MeSi]−; 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)­IrI] in THF at room temperature to selectively afford
a 16-electron hydrido–hydroxo complex [(PSiP-tBu)­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)­(H2O)] was isolated and structurally characterized by X-ray crystallography.