Simultaneous Binding of Ruthenium(II) [(1,10-Phenanthroline) 2 dipyridophenazine] 2+ and Minor Groove Binder 4‘,6-Diamidino-2-phenylindole to Poly[d(A−T) 2 ] at High Binding Densities: Observation of Fluorescence Resonance Energy Trasfer Across the DNA Stem