ENCAPSULATED IRIDIUM(III) COMPLEXES

A composition is described comprising an iridium(III) complex of formula [IrCp*(C^N)L]n+Xn, wherein X is an anion and [IrCp*(C^N)L] is a cationic complex, wherein the complex [IrCp*(C^N)L] is independently selected from a compound of formula Ia or a compound of formula Ib, wherein L is a group containing at least one coordination atom selected from the group consisting of N, O, S, or P, and wherein the iridium(III) complex is encapsulated in nanoparticles, as well as compositions for use as photosensitizers in antitumor photodynamic therapy and processes for obtaining the same.