Bis-phenanthroline copper(II) phthalate complexes are potent in vitro antitumour agents with 'self-activating' metallo-nuclease and DNA binding properties.

Three, structurally characterised, bis-phen Cu(II) complexes of the phthalate isomers display rapid, low micromolar in vitro cytotoxicity against a range of epithelial tumour cells. The complexes induce relaxation of supercoiled plasmid DNA in the absence of external reducing agents and display efficient CT-DNA, Poly[d(A-T)](2) and Poly[d(G-C)](2) binding.