Luminescent Ruthenium(II) Complex Bearing Bipyridine and N-Heterocyclic Carbene-based C ∧ N ∧ C Pincer Ligand for Live-Cell Imaging of Endocytosis

Luminescent ruthenium(II)-cyanide complex with N-heterocyclic carbene pincer ligand C∧N∧C = 2,6-bis(1-butylimidazol-2-ylidene)pyridine and 2,2′-bipyridine (bpy) shows minimal cytotoxicity to both human breast carcinoma cell (MCF-7) and human retinal pigmented epithelium cell (RPE) in a wide range of concentration (0.1–500 μM), and can be used for the luminescent imaging of endocytosis of the complex in these cells.