Synthesis of a Functionalized Salen−Copper Complex and Its Interaction with DNA

An original procedure for efficient synthesis of a functionalized salen·copper complex is reported. The mode of binding to DNA of the salen·CuII complex was investigated by viscometry as well as by absorption, circular, and linear dichroism spectroscopy. The complex can induce DNA strand breakage in the presence of a reducing agent as revealed by a plasmid cleavage assay. The spectroscopic and biochemical data indicate that the salen·CuII complex induces single-stranded breaks via an interaction within one of the grooves of the double helix.