<i>N</i>‐Methyl‐2, 2'‐Dipicolylamine Complexes as Potential Models for Metal‐Mediated Base Pairs

Abstract

Abstract Metal‐mediated base pairs can be used to insert metal ions into nucleic acids at precisely defined positions. As structural data on the resulting metal‐modified DNA are scarce, appropriate model complexes need to be synthesized and structurally characterized. Accordingly, the molecular structures of nine transition metal complexes of N ‐methyl‐2, 2'‐dipicolylamine (dipic) are reported. In combination with an azole‐containing artificial nucleoside, this tridentate ligand had recently been used to generate metal‐mediated base pairs ( Chem. Commun. 2011 , 47 , 11041–11043). The Pd II and Pt II complexes reported here confirm that the formation of planar complexes (as required for a metal‐mediated base pair) comprising N ‐methyl‐2, 2'‐dipicolylamine is possible. Two Hg II complexes with differing stoichiometry indicate that a planar structure might also be formed with this metal ion, even though it is not favored. In the complex [Ag 2 (dipic) 2 ](ClO 4 ) 2 , the two Ag I ions are located close to one another with an Ag ··· Ag distance of 2.9152(3) Å, suggesting the presence of a strong argentophilic interaction.