Protein Staining Agents from Cationic and Neutral Luminescent Iridium(III) Complexes

Seven luminescent iridium(III) complexes were prepared to investigate the relationships between chemical structures and properties of protein staining. For the first time, the effect of the main ligand, the π conjugation effect of the ancillary ligand, and the charge effect of organometallic complexes on protein staining has been revealed. Most importantly, this study gives the first experimental evidence of the potential applications of charge‐neutral organometallic complexes in protein staining, which could open an avenue of exploiting novel protein staining agents in the future.