Probing DNA photocleavage efficiencies of Ru(II) polypyridyl complexes: Theoretical calculation of redox potentials

Theoretical studies on DNA-photocleavage efficiencies of Ru(II) polypyridyl complexes 1–4 have been carried out using the density functional theory (DFT) method. First, the redox potentials of Ru(II) polypyridyl complex were computed using different functionals. Secondly, the redox potentials of complexes 1–4 in the excited state were accurately computed. Finally, the trend in DNA-photocleavage efficiencies (φ) of complexes 1–4, i.e., φ (4) > φ (3) > φ (2) > φ (1), were reasonably explained by the excited-state reduction potentials. In particular, the DNA-photocleavage efficiency of a new Ru(II) complex 4 was predicted.