Ruthenium(II) bipyridine complexes with pendant anthracenyl and naphthyl moieties: A strategy for a ROS generator with DNA binding selectivity

• Anthracenyl and naphthyl-bipyridine coordinated to ruthenium(II) show ROS photogeneration.
• Ruthenium(II) anthracenyl bipyridine showed production of both singlet oxygen and hydroxyl radical.
• Anthracenyl-bipyridine moiety promoted binding to DNA while enhanced efficient photocleavage under visible light.
• Potential application as a tool in cellular biology (CALI) and therapy.

Coordination compounds that combine selective DNA binding with reactive oxygen species (ROS) generation production have been sought as tools for cell biology studies and cancer therapy. In this respect, the contribution of this work lies on the use of anthracenyl (Ru-Anth) and naphthalyl-pedant (Ru-Naph) ruthenium(II) bipyridine complexes, which were synthesized and fully characterized by spectroscopic and electrochemical techniques. Both complexes presented efficient 1O2 photogeneration, with anthracenyl-pendant showing higher quantum yields as well as OH production. The DNA photocleavage showed to be dependent on the energy of the exciting radiations thus indicating that the photocleavage process mostly involves the 1O2 species. In comparison to Ru-Naph, the higher efficiency of the Ru-Anth complex toward the DNA cleavage was assigned to the presence of the anthracenyl moiety that provides an efficient channel to generate 1O2. These findings have validated the use of conjugated organic ligands with metal complexes as a strategy to bring together binding and photooxidative properties.

Anthracenyl (Ru-Anth) and naphthalyl-pedant (Ru-Naph) ruthenium(II) bipyridine complexes presented efficient 1O2 photogeneration, with anthracenyl-pendant showing higher quantum yields. In comparison to Ru-Naph, the higher efficiency of Ru-Anth toward the DNA cleavage was assigned to the presence of the anthracenyl moiety that provides an efficient channel to generate 1O2.Figure optionsDownload as PowerPoint slide