A stable zinc(II)-mediated base pair was formed within a parallel-stranded DNA duplex comprising a GNA (glycol nucleic acid) functionalized nucleoside analog containing the artificial nucleobase 1H-imidazo[4,5-f][1,10]phenanthroline (P). The formation of the metal-mediated base pair was confirmed by UV and CD spectroscopic analyses. In the Zn(II)-mediated homo base pairs of the type P–Zn(II)–P, the metal ion adopts a [2 + 2] coordination environment. CD spectroscopic data suggest that the chiral metal complex is formed enantiospecifically, likely induced by the helical chirality of the surrounding DNA duplex. The Zn(II)-mediated base pair stabilizes the DNA oligonucleotide duplex by 9 °C. This stable Zn(II)-mediated base pair within a parallel-stranded duplex extends the scope of site-specific functionalization of nucleic acids by virtue of metal-mediated base pairing.

稳定的锌（II）介导的碱基对在包含GNA（乙二醇核酸）官能化核苷类似物的平行链DNA双链体中形成，该类似物包含人工核碱基1 H-咪唑并[4,5- f ] [1,10]菲咯啉（P）。通过UV和CD光谱分析确认了金属介导的碱基对的形成。在Zn（II）介导的P –Zn（II）– P型同源碱基对中，金属离子采用[2 + 2]配位环境。CD光谱数据表明，手性金属络合物是对映体特异性形成的，可能是由周围DNA双链体的螺旋手性诱导的。Zn（II）介导的碱基对可在9°C的温度下稳定DNA寡核苷酸双链体。平行链双链体中这种稳定的Zn（II）介导的碱基对凭借金属介导的碱基配对扩展了核酸的位点特异性功能化的范围。