linkers were synthesized. The effect of the phenanthrene moiety on duplexstability at different positions was investigated. Placement of two phenanthrene residues in opposite positions had a slightly positive effect on duplexstability. This positive effect was further increased, when two phenanthrene pairs were juxtaposed. In contrast, introduction of a single phenanthrene unit opposite to an adenosine
Self-complementary oligodeoxynucleotides containing 3,6-disubstituted phenanthrenes adopt highly stable, hairpin-like structures. The thermodynamic stability of the hairpin mimics depends on the overall length of the phenanthrene building block. Hairpin loops composed of a phenanthrene-3,6-dicarboxamide and ethylene linkers were found to be optimal. The hairpin mimics are more stable than the analogous