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.