Multinuclear Ir-BODIPY complexes: Synthesis and binding studies

The use of fluorescent based metal complexes is a flourishing area of research particularly in the field of chemical biology. Herein, we synthesized and fully characterized a series of three new multinuclear iridium based-BODIPY metal complexes in high yield. The free ligands and their metal complexes are highly emissive due to the presence of the BODIPY chromophore. Owing to the growing popularity of metal complexes as bioactive drug candidates, we performed their binding studies with DNA and protein, in vitro. Their dose dependent tendency to interact with DNA and ability to quench the intrinsic fluorescence of BSA protein confirmed their high bioactivity. With significant hyperchromic and red shifts observed with dsDNA, and prominent decline in the spectra of ssDNA, complex Ir3L3 showed the highest electrostatic interaction with genomic DNA among all complexes. Likewise, Ir3L3 also showed maximum dose-dependent quenching of the BSA protein in both emission as well as absorbance spectra, indicating its ability to interact with protein.