Interaction of [Pt(en)(phen)](2+) and [Pt(en)(phi)](2+) with the hexanucleotide d(GTCGAC)(2) : evidence for minor groove binding

There is considerable interest in the interactions of inert transition metal complexes with nucleic acids. Metal complexes have been used in studying the principles of nucleic acid recognition, in probing the tertiary structures of nucleic acids, as artificial nucleases, as luminescent probes for DNA, and in examining electron transfer mediated by DNA. If new metallointercalators are to be designed and used for their many potential DNA-related applications, it is important to establish those factors that govern the groove access of the intercalator. Octahedral rhodium(III) complexes based upon the phenanthrenequinone diimine (phi) ligand have been unambiguously shown to intercalate from the DNA major groove. However, the groove-binding preference of octahedral polypyridyl-based metallointercalators is still the subject of controversy.