Steric effects on binding O_2, SO_2 and CH_3I to square-planar iridium(I) complexes, trans-Ir(CO)(Cl)(P(I-Pr)_3)_2 and trans-Ir(CO)(Cl)(P(t-Bu)_2Me)_2

摘要

Steric and electronic effects of phosphine ligands onbinding of molecules to iridium(I) have been probed by studyingreactions of O_2, SO_2 and CH_3I with trans-Ir(CO)(Cl)(P(I-Pr)_3)_2 and trans-Ir(CO)(Cl)(P(t-Bu)_2Me)_2 for comparisonto known reactions with trans-Ir(CO)(Cl)L_2(L=PPh_3, P(p-tolyl)_3 and Pcy_3). Reaction of O_2 is significantly retarded byincreasing size of the ligand while reaction of SO_2 is essentiallyunaffected by the nature of the phosphine ligand. Reaction ofCH_3I with trans-Ir(CO)(Cl)(P(t-Bu)_2Me)_2 produces twoproducts which have been characterized by NMR and infrared spectroscopy.