Three new organoiridium complexes, [Ir(COD)(diphos)]Cl (diphos = R2PCH2CH2PR2, R = Me, Et, Ph; COD = cyclooctadiene) are synthesized from [Ir(COD)(m-Cl)]2 and diphosphine in molar ratio 1:2, and characterized by means of IR, 1H NMR, elec. conductivity and elemental analyses. The reactions of these complexes with MeCN in the presence of CO or CO2 gave [(H)Ir(diphos)(CO)2(COCH2CN)]Cl or products containing Ir-OCOR groups suggest that these complexes are able to activate the C-H bonds of MeCN and promote the insertion reaction of CO, CO2 with the Ir-C bond.

Key words: ORGANO PHOSPHORUS COMPOUNDS, PHOSPHINE, CHEMICAL BONDS, INSERTION REACTION, MOLECULAR ORBITAL THEORY, CARBOXY GROUP, IRIDIUM COMPLEX, CARBONYL GROUP, ORGANO TRANSITION METAL COMPLEX, HYBRIDIZATION