Artificial metallo‐DNA towards discrete metal arrays

Abstract

AbstractDNA shows promise as a provider of a structural basis for the “bottom‐up” fabrication of functionalized molecular building blocks. In particular, the replacement of hydrogen‐bonded DNA base pairing for alternative one could possibly provide a novel tool for re‐engineering DNA as well as for biological applications. This review describes our recent approaches to metal‐based strategy directed towards self‐assembled metal arrays within DNAs. Recently, we reported the synthesis of a series of artificial oligonucleotides, d(5′‐GHnC‐3′) (n = 1‐5), using hydroxypyridone nucleobases (H) as flat bidentate ligands. Right‐handed double helices of the oligonucleotides, nCu2+·d(5′‐GHnC‐3′)2 (n = 1‐5), are quantitatively formed through Cu2+‐mediated alternative base pairing (H‐Cu2+‐H), where the Cu2+ ions are aligned along the helix axes inside the duplexes with the Cu2+‐Cu2+ distance of 3.7 ± 0.1 Å. The Cu2+ ions are coupled in a ferromagnetic manner with one another through unpaired d electrons to form magnetic chains. This strategy represents a new method for self‐assembled metal arrays in a predesigned fashion, leading to the possibility of metal‐based molecular devices such as molecular magnets and wires.