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 b ecause the interaction with the polynucleotides inhibits solvent-induc ed quenching. Hydrophobic forces strongly shape the binding which prob ably does not conform to a type of intercalation. In contrast, the cop per porphyrin Cu(TMpyP4) intercalates into DNA that contains GC base p airs. It emits when intercalated but not when groove bound. Finally, w e describe preliminary studies of emissive platinum(II) terpyridine co mplexes.