Fig. 4.

Intercalation of the dppz ligand. (A) The C2-G9 base pair, showing the stacking of G9 onto the central pyrazine ring of the dppz ligand. (B) The reverse Watson–Crick T1-A10 base pair formed by the flipped-out A10. The purine ring of A10 is again stacked onto the pyrazine ring of the dppz. Bases are color coded as in Fig. 1, and the ruthenium ligands as in Fig. 3, but using a paler shade of pink for the dppz ligand for clarity.