Synthesis, DNA photocleavage, singlet oxygen photogeneration and two photon absorption properties of ruthenium-phenanthroline porphyrins

Through a new synthetic route, three ruthenium-phenanthroline porphyrins (RPP1, RPP2 and RPP3) were prepared. Their photophysical and photochemical properties, such as DNA photocleavage activity, singlet-oxygen photogeneration and two-photon absorption (2PA) were evaluated. These porphyrins 1–3 had substantial photocleavage activities, with 71%, 74% and 38% observed at 20 μM. The porphyrins with different substituents on phenathroline group had similar singlet oxygen quantum yields, with ΦΔ values at 0.52, 0.47 and 0.41, respectively. The 2PA cross-section (σ(2)) values of RPP 1–3, measured by the Z-scan method, were calculated to be 152, 172 and 135 GM, respectively, which were around 5-fold higher than that of H2TPP . Thus, these porphyrins, with their good photocleavage activities, 1 O 2 quantum yields and high 2PA cross section, suggest great potential as photodynamic therapeutic agents.