Highly efficient recognition of native TpT by artificial ditopic hydrogen-bonding receptors possessing a conformationally well-defined linkage

Synthesis and binding affinity of rationally designed artificial ditopic nucleobase receptors are reported. The ditopic receptors were designed to recognize thyminethymine dinucleotides by their two hydrogen-bonding moieties, which are connected to conformationally well-defined linkages such as ferrocene and biphenylene. The ditopic receptors exhibited a remarkably strong binding affinity for lipophilic TpT analogue in CDCl₃/DMSO-d₆ (85:15, v/v). The binding affinity of the ditopic receptors for the dinucleotide was so high that even native TpT was extracted by them into CDCl₃. Detailed comparisons for the recognition abilities of the ditopic receptors were also conducted.