Oxidative Addition Reactions of Low-Valent Complexes of Iridium

by Reed, Christopher Alan

This study concerns the synthesis, structure and reactivity of d10 and d8 complexes of iridium. Emphasis has been placed on complexes containing a nitrosy1 ligand and on those which are coordinatively unsaturated. Their oxidative addition reactions show considerable analogy to the more familiar dl0 and d8 platinum group complexes. Several new ligand reactions are reported. The d10 complex Ir(N0)(PPh3)3 reacts with hydrogen halides in excess giving IrX3(NH2OH)(PP3)2 (X = C1, Br) converting bound nitrosyl to bound hydroxylamine while reaction with oxygen gives the dimer [Ir(NO)(PPh3)]20. The structures of these complexes and other products of oxidative addition are discussed in the light of recent X-ray crystal data. Linear and very bent Ir-N-0 linkages exist. Both types of nitrosyl linkage are believed to exist in [IrH(NO)(PPh3)3]C104 depending on the crystalline form. Triphenylarsine analogues show very similar reactivity to the triphenylphosphine comlexes.