Iminopyridonato Iridium Complexes: O-Functionalization via C-X Bond Cleavage

Abstract

A new series of 2-pyridonato-based Ir(III) half-sandwich complexes [(η5-Cp*)IrX(2-{(2,6-iPr2-C6H3)N=CH}-C5H3N-6-(O))] (3: X = Cl; 4: X = I) were prepared via a thermally initiated demethylation of the corresponding ionic complexes [(η5-Cp*)IrX(κ2-{2-[(2,6-iPr2-C6H3)N=CH]-6-(OMe)C5H3N})](X) (1: X = Cl; 2: X = I). These neutral complexes 3 and 4 were further studied as versatile precursors for the preparation of unprecedented polymetallic Ir-Zn and Ir-Zn-Ru complexes. Remarkably, complexes 3 and 4 could activate C(sp3)-X bonds, leading to the isolation of several O-substituted ionic products. Alongside this O-functionalization, substitution of the Ir–Cl bond by Ir–X (X = Br or I) was also observed during this reaction and both processes were investigated in detail to provide mechanistic insight.