Reaction of Cyclometalated Phosphine Chloride Iridium(III) Complexes with Imidazole

A series of iridium complexes with various cyclometalated ligands and phosphines [Ir(N^C)2(PR3)Cl], where N^C = 2-(benzothiophen-3-yl)pyridine and 2-phenylpyridine and R = phenyl and p-methoxyphenyl, were obtained. It was shown that the complexes of this type react with imidazole under mild conditions. The phosphine and chloride ligands are consecutively substituted to give imidazole-containing derivatives. The photophysical properties of all the synthesized compounds were investigated in detail. The imidazole-containing complexes demonstrate efficient triplet luminescence in solution with quantum yields up to 60%, which is sensitive to molecular oxygen.