Reactions of tri(hydrido)(p-tolyl isocyanide)bis(triphenylarsine)iridium(III) with chelating ligands: spectroscopic and magnetic study

Abstract

Reactions of [IrH₃(AsPh₃)₂(CNC₆H₄Me-p)] with chelating ligands yield substitution products having the metal in various oxidation states depending on the nature of the ligand. Carboxylic acids, pentane-2,4-dione, and quadridentate Schiff bases give iridium(II) monomeric paramagnetic complexes; amino- and hydroxy-acids and o-amino- and o-hydroxy-phenols give paramagnetic iridium(IV) products. The presence of highly electron-attracting groups in the co-ordination sphere keeps Ir in the oxidation state III. All the complexes have been characterised by their vibrational, electronic, and magnetic properties, and in some cases the most probable ground-state electronic configuration of Ir has been suggested. Ligand-field properties favourable to each oxidation state are discussed.