Near-infrared phosphorescent cyclometalated platinum (II) and iridium (III) complexes with metformin moiety: Design and study towards anticancer theranostic agents.

By rational altering the structure of CN auxiliary ligand, Near-infrared (NIR) phosphorescent cyclometalated platinum (II) and iridium (III) complexes with metformin (Met) have been successfully obtained and characterized. The dissociation of Met in aqueous solution can be accelerated by addition of Glutathione (GSH) and alleviated by drop of histidine, accompanied with a significant decay change of deep red phosphorescence. Besides, Pt3 and Ir1 with moiety of btpq mainly selectively targeted and located in Mitochondrial, while Pt1 of ppy and Pt2 with thpy mainly accumulated in endoplasmic reticulum.