Ir(III)-ciclopentadienyl-pyridinyl-quinoline complexes: solution properties and polynucleotides binding

There is an emerging interest in applying inorganic and organometallic transition metal complexes like new anticancer drug capable of interacting with DNA. Recently, studies have focused on half-sandwich Ir(III) anticancer complexes, that can attack the DNA or perturbate the redox status of cells. In this work we studied the interaction between the iridium complex shown in Figure 1 and biosubstrates as DNA, RNA and BSA. Firstly, the properties of the metal complex alone were analysed: the chloride exchange process (to give Ir-H₂O from Ir-Cl) and the acidity constants. Then, the possible binding reaction of the two species Ir-H₂O and Ir-OH¯, with biosubstrates was analysed through spectrophotometry, viscometry, circular dichroism and stopped-flow kinetics. The results obtained show some interesting interactions taking place, that will be discussed.