A Family of Hydrazone-Based Nucleosides for Use in Metal-Mediated Base Pairs

摘要

A new family of hydrazone-based nucleosides for use in metal-mediated base pairs was devised. The artificial nucleobases are derivatives of the papy ligand (papy = pyridinecarboxaldehyde-2'-pyridylhydrazone). By replacing the pendant pyridine moiety in papy by furan and thiophene, respectively, tridentate nucleosides with N,N,N-, N,N,O- and N,N,S-donor sites were obtained. As only a few transition metal complexes with pendant furan ligands have been reported, a model nucleobase for the N,N,O-donor nucleoside was synthesized. The molecular structures of its Cu~(2+), Ni~(2+), and Co~(2+) complexes are reported. In all complexes, only weak M-O(furan) bonding is observed. The Co~(2+) complex displays a pentagonal bipyramidal coordination arrangement. In general, the structures of the metal complexes suggest that the respective nucleosides can be applied in metal-mediated base pairs.