THERMAL AND PHOTOCHEMICAL-TRANSFORMATIONS OF ORGANOIRIDIUM PHOSPHIDE COMPLEXES - MECHANISTIC STUDIES ON CARBON PHOSPHORUS BOND FORMATION TO GENERATE CYCLOMETALATED HYDRIDE COMPLEXES BY ALPHA-HYDRIDE ABSTRACTION

{The thermal and photolytic transformations of a series of methyliridium(III) phosphide complexes are described. Complexes of the formula Ir(CH3)PR2[N(SiMe2CH2PPh2)2] (R = Ph, Me) rearrange thermally to generate the corresponding cyclometalated derivatives fac-Ir(eta-2-CH2PR2)H[N(SiMe2CH2PPh2)2]; continued thermolysis results in the formation of the iridium(I) phosphine complexes Ir(PMeR2)[N(SiMe2CH2PPh2)2]. Under photolytic conditions the phosphide derivatives rearrange directly to the phosphine complexes with no observable intermediates. The phenylphosphide complex Ir(CH3)PHPh[N-(SiMe2CH2PPh2)2] rearranges directly to the phosphine derivative Ir(PHPhMe)[N(SiMe2CH2PPh2)2] both thermally and photolytically with no observable intermediates. Crystals of lr(CH3)PPh2[N(SiMe2CH2PPh2)2] are monoclinic with a = 13.506 (3) angstrom