Light induced DNA scission by a luminescent mixed-ligand uranyl complex

Efficient cleavage of supercoiled pBR322 DNA by X-ray crystallographically characterized complex, [UO2(phen)(aba)(OC2H5)] (phen = 1,10-phenanthroline; aba = 4-dimethylamino benzoate) has been observed on irradiation with UV (350 nm) or visible light without any external additives through a mechanistic pathway involving singlet oxygen. This complex having 1,10-phenanthroline as an intercalator/binder to supercoiled DNA and N,N-(dimethylamino)benzoate as a chromophore.