Synthesis of 5,12-dioxocyclam nickel (II) complexes having quinoxaline substituents at the 6 and 13 positions as potential DNA bis-intercalating and cleaving agents

Several dioxocyclams containing quinoxaline moieties, as well as their nickel(II) complexes were synthesized and studied for their ability to bind and oxidatively cleave DNA. Although no evidence for binding by intercalation was found, the ability of the Ni(II) complexes to cleave DNA in the presence of Oxone was strongly dependent on both the nature and the spatial orientation of the quinoxaline moieties, suggesting at least transient association of these complexes with DNA.