Heterochiral vs. Homochiral Linkage of Emissive Iridium(III) Complexes with D ‐Penicillaminate: Drastic Change in Emission Induced by Silver(I) Linkage

Reactions of [{Ir(ppy or ppy‐CF3)2}2(μ‐Cl)2] {Hppy = 2‐phenylpyridine, Hppy‐CF3 = 2‐[3,5‐bis(trifluoromethyl)phenyl]pyridine} with D‐penicillamine (D‐H2pen) afforded emissive IrIII mononuclear complexes [Ir(ppy or ppy‐CF3)2(D‐Hpen‐N,S)] as a 1:1 mixture of the ΔD/ΛD isomers. These complexes were converted into IrIIIAgIIrIII trinuclear structures in [Ag{Ir(D‐pen‐N,S)(ppy or ppy‐CF3)2}{Ir(D‐Hpen‐N,S)(ppy or ppy‐CF3)2}] by treatment with AgNO3, which led to a drastic blueshift of the emission bands. Whereas the (ppy)IrIIIAgIIrIII complex produced the heterochiral ΔDΛD isomer, the ppy‐CF3 complex gave the homochiral ΔDΔD and ΛDΛD isomers that could completely be separated by crystallization. It was found that the quantum efficiency of the emission band for the ΔDΔD isomer is much lower than that for the ΛDΛD isomer.