Self-Assembled Nanostructure Library from Monodisperse Sequence-Defined Oligo(phosphodiester)s

Natural biopolymers achieve information storage, molecular recognition and catalysis efficiently through sequence-control. To be able to mimic such properties, self-assembly studies of artificial sequence-defined oligomers is of great interest. In this paper, we show the use of hydrophilic, lipophilic, aromatic and fluorophilic monomers to synthesize a large library of truly monodisperse sequence-defined block co-oligo(phosphodiester)s. Automated and accurate control over the sequence allowed to rationally study the degree of polymerisation, blocks ratio, chemical composition and orthogonal supramolecular interactions influence on self-assembly. Interestingly, our studies revealed remarkable morphological changes (spheres to nanosheets) caused by very small differences between polymers, e.g., polymers differing by a single monomer unit. Inverting block sequence in multi-block copolymers also caused a dramatic increase in micelle size. Conventional polymerization does not allow the exploration of these subtle variations in polymer sequence or composition. Therefore, fast synthesis and purification of a variety of oligomers with slightly different sequences allows studying the supramolecular chemistry of precision oligomers in a systematic way. It paves the way to the rational design of functional sequence-defined polymers.