The unusual compound of formula [Ir2(μ-Pz)2(CH3)(CO)2(PiPr 3)2](ClO4) (3) has been prepared. This complex is the proposed intermediate species for the SN2 oxidative addition of methyl iodide to the dinuclear compound [Ir(μ-Pz)(CO)(PiPr3)]2 (1). The spectroscopic and X-ray diffraction data obtained for 3, together with EHMO calculations and reactivity studies, indicate that the compound can be described as an Ir(III)-Ir(I) species containing a weak metal-metal bond. The implications of these electronic features in the regioselectivity of halocarbons oxidative additions to dinuclear complexes are discussed.

This work received financial support from the Spanish ‘Dirección General de Investigación Científica y Técnica’ (DGICYT) (projects no. PB94-1186, and PB95-0318).

Peer Reviewed