Diruthenium complexes incorporating carboxylated chalcones with phenyl or ferrocenyl units: Synthesis, structural, electrochemical and DNA binding studies

A total of eight diruthenium sawhorse and cationic complexes incorporating carboxylated chalcones with phenyl or ferrocenyl units have been synthesized and characterized. The electrochemical behavior of the sawhorse and cationic complexes incorporating the ferrocenyl moiety have been studied by cyclic voltammetry. For the cationic complexes both the diruthenium core and the ferrocenyl unit undergo oxidation, in contrast only the ferrocenyl moieties for the sawhorse complexes were oxidized. The enhanced solubility of the cationic complexes over the neutral sawhorse compounds in aqueous medium enabled DNA binding studies to be undertaken for the former. All of the cationic complexes could bind to DNA, and displayed better selectivity for quadruplex over duplex DNA. These results indicate that diruthenium cationic complexes are able to bind to quadruplex DNA and have the potential to function as telomerase inhibitors.