Governing the oxidative addition of iodine to gold(I) complexes by ligand tuning

The impact of addition of iodine to gold compounds which is strongly ligand-dependent and indicate a threshold in the oxidation potentials was investigated. A large series of tertiary phosphines were used as ligands for the oxidative addition of iodine. The reactions were followed by ³¹P NMR spectroscopy and the products crystallized from dichromethane-pentane solutions. Complexes with small triakylphosphines were readily oxidized, while those with more bulky ligands were not. No oxidation took place when the ligands were taken from the triaryphosphine series.