Soft Metal-Mediated Base Pairing with Novel Synthetic Nucleosides Possessing an <i>O</i>,<i>S</i>-Donor Ligand

Metal-mediated base pairing with artificial ligand-bearing nucleosides allows site-selective metal incorporation inside DNA duplexes. In particular, this strategy has provided a general way of discrete, heterogeneous metal arrays in a programmable manner. To increase the kind of metallo-building blocks, we have newly synthesized two artificial nucleosides which have an O,S-donor ligand as the nucleobase moiety, mercaptopyridone (M) and hydroxypyridinethione (S). These nucleosides were found to efficiently form metal-mediated base pairs with soft transition metal ions such as Pd2+ and Pt2+.