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.
Moždiak et al. (Sun,) studied this question.