Dynamers at the Solid-Liquid Interface: Controlling the Reversible Assembly/Reassembly Process between Two Highly Ordered Supramolecular Guanine Motifs

摘要

Complex systems and phenomena in nature are dominated by reversible noncovalent interactions. Nucleobases, which are essential components of the genetic material in all living organisms, encode sophisticated programs for self-assembly into highly ordered and complex architectures, such as the fascinating double helix of DNA. Alongside Watson-Crick base pairing, which directs the formation of the helical structure of DNA, nucleobases can interact through other hydrogen-bonded motifs to form various complex supra-molecular architectures, such as guanine (G) quadru-plexes. The G quartet G4, an hydrogen-bonded macrocycle typically formed by cation-templated assembly, was first identified in 1962 as the basis for the aggregation of 5'-guanosine monophosphate (5'-GMP), and fits particularly well with contemporary studies in molecular self-assembly and noncovalent synthesis. Guanine is an extremely versatile building block: depending on its environment, it is able to self-assemble into various discrete architectures including dimers, ribbons, and macrocycles.' In the presence of certain cations, either G4-based octamers or columnar aggregates (supramolecular polymers) can be formed, depending on the concentration of the cation and nucleobase. The guanine-based structures are interesting for applications in organic electronics and synthesis of supramolecular hydrogels,whereas G quartets are known to have potential in several biological processes and in anticancer drug design, as they can act as enzyme telomerase inhibitors, and therefore are of importance for controlling tumor immortalization.