Diverse Cation-Promoted Reactivity of Iridium Carbonyl Pincer-Crown Ether Complexes

Several new iridium­(I) and iridium­(III) carbonyl complexes supported by aminophosphinite pincer ligands have been prepared and characterized. A surprising diversity of reaction pathways was encountered upon treatment of Ir carbonyl complexes with Li+, Na+, Ca2+, and La3+ salts. Iridium­(III) hydridocarbonyl chloride complexes underwent either halide abstraction or halide substitution reactions, whereas iridium­(I) carbonyl complexes underwent protonative oxidative addition reactions. When the nitrogen donor of the pincer ligand is an aza-crown ether macrocycle, cation–macrocycle interactions could be supported, leading to divergent reactivity in some cases.