Synthesis of homoleptic tris(organo-chelate)iridium(III) complexes by spontaneous ortho-metallation of electronrich olefin-derived N, N′-diarylcarbene ligands and the X-ray structures of fac-[ [formula omitted]6H 3Me- p} 3] and mer- [formula omitted]6H 3Me- p} 2 { [formula omitted]C 6H 4Me- p}Cl (a product of HCl cleavage)

Abstract

Treatment of [{Ir(COD)(μ-Cl)} 2] with excess of the electron-rich olefin [ CN(Ar)(CH 2) 2N Ar] 2 (abbreviated as (L Ar) 2, Ar = C 6H 4Me- p or C 6H 4OMe- p) affords the ortho-metallated tricycle [ Ir(L Ar ) 3], which for Ar = C 6H 4Me- p (Ia) with HCL yields [ Ir(L Ar ) 2(L Ar)]Cl (IV); X-ray data show that in IV there is an unexpectedly close Ir⋯C( o-aryl) contact (2;52(1) Å) involving the “free” L Ar which compares with an IrC( o-aryl) distance of 2.09(3) Å in Ia or 2.07(3) Å in the ortho-metallated L Ar ligand of complex IV.