Binuclear ruthenium(II) complexes of 4,4′-azopyridine bridging ligand as anticancer agents: synthesis, characterization, and in vitro cytotoxicity studies

DNA‐Targeting RuII‐Polypyridyl Complex with a Long‐Lived Intraligand Excited State as a Potential Photodynamic Therapy Agent

“…As [Ru(bpy) 2 dppz] ⋅ 2 PF 6 was reported to be able to interact with DNA, [10, 11] the DNA binding and photodamaging properties of the new complexes Ru1 and Ru2 were explored. The DNA binding abilities of the complexes were studied by fluorescence competitive binding experiments [22, 23] . As shown in Figure S3 (in the Supporting Information), the emission intensities of DNA‐bound ethidium bromide (EtBr) were greatly decreased upon addition of Ru1 , Ru2 , and [Ru(bpy) 2 (dppz)] ⋅ 2 PF 6 , possibly attributed to the replacement of EtBr by these Ru II complexes.…”

“…The DNA binding abilities of the complexes weres tudiedb yf luorescencec ompetitive binding experiments. [22,23] As shown in Figure S3 (in the Supporting Information),t he emission intensities of DNA-bound ethidium bromide (EtBr) were greatly decreasedu pon addition of Ru1, Ru2,a nd [Ru(bpy) 2 (dppz)]•2PF 6 , possibly attributed to the replacement of EtBr by theseR u II complexes.H owever,i ti sw orth noting that the Ru II complexes can absorb the excitation light in this assay.W ith the increased amount of Ru II complexes, the excitation light could be absorbed, resulting in fluorescencequenching.…”