Syntheses of new water-soluble dicobalt complexes having two cobaltcarbon bonds and their ability for DNA cleavage

One-pot syntheses of new water-soluble dicobalt complexes having two cobaltcarbon bonds are reported. The complexes were characterized by 1H NMR and UV–vis spectroscopies as well as ESI-MS. These complexes were photosensitive, and photo-cleavage of the cobaltcarbon bonds upon irradiation with visible light produced methyl radicals which were detected by ESR spin-trapping techniques. The dicobalt complexes exhibited high ability for DNA cleavage in comparison with that for the corresponding monocobalt complex.