COORDINATIVELY UNSATURATED EXCITED-STATES AND DNA-BINDING INTERACTIONS

We describe luminescence studies of a series of four-coordinate d-10, d9 and d8 systems. The phenanthroline complexes, Cu(dmpp)2+ and Cu(bcp)2+, emit in aqueous methanol solutions containing excess DNA or RNA because the interaction with the polynucleotides inhibits solvent-induced quenching. Hydrophobic forces strongly shape the binding which probably does not conform to a type of intercalation. In contrast, the copper porphyrin Cu(TMpyP4) intercalates into DNA that contains GC base pairs. It emits when intercalated but not when groove bound. Finally, we describe preliminary studies of emissive platinum(II) terpyridine complexes.