Homo- and Heteroleptic Phototoxic Dinuclear Metallo-Intercalators Based on Ru (dppn) Intercalating Moieties: Synthesis, Optical, and Biological Studies.

Using a new mononuclear "building block," for the first time, a dinuclear Ru (dppn) complex and a heteroleptic system containing both Ru (dppz) and Ru (dppn) moieties are reported. The complexes, including the mixed dppz/dppn system, are O sensitizers. However, unlike the homoleptic dppn systems, the mixed dppz/dppn complex also displays a luminescence "switch on" DNA light-switch effect. In both cisplatin sensitive and resistant human ovarian carcinoma lines the dinuclear complexes show enhanced uptake compared to their mononuclear analogue. Thanks to a favorable combination of singlet oxygen generation and cellular uptake properties all three of the new complexes are phototoxic and display potent activity against chemotherapeutically resistant cells.