Phosphorescent cationic iridium(III) complexes dynamically bound to cyclodextrin vesicles: applications in live cell imaging

We report cationic Ir(III) complexes functionalized with adamantyl groups designed to bind to beta-cyclodextrin vesicles (CDV) with high affinity (K-a = 1 x 10(6) M-1). The emission of the complexes is tuned by changing the nature of the cyclometalating ligands. The host-guest adduct of CDV and Ir(III) complexes shows increased and significantly blue-shifted emission due to the lower mobility of the Ir(III)-complexes residing in the less polar environment of the vesicle surface. Ir(III)-decorated CDV are efficiently taken up by cells and can be used in live cell imaging. The CDV act as carriers to transport the phosphorescent complexes into cells where they selectively stain mitochondria.