Living supramolecular polymerization realized through a biomimetic approach

Abstract

Various conventional reactions in polymer chemistry have been translated to the supramolecular domain, yet it has remained challenging to devise living supramolecular polymerization. To achieve this, self-organization occurring far from thermodynamic equilibrium--ubiquitously observed in nature--must take place. Prion infection is one example that can be observed in biological systems. Here, we present an 'artificial infection' process in which porphyrin-based monomers assemble into nanoparticles, and are then converted into nanofibres in the presence of an aliquot of the nanofibre, which acts as a 'pathogen'. We have investigated the assembly phenomenon using isodesmic and cooperative models and found that it occurs through a delicate interplay of these two aggregation pathways. Using this understanding of the mechanism taking place, we have designed a living supramolecular polymerization of the porphyrin-based monomers. Despite the fact that the polymerization is non-covalent, the reaction kinetics are analogous to that of conventional chain growth polymerization, and the supramolecular polymers were synthesized with controlled length and narrow polydispersity.

Monodisperse Cylindrical Micelles and Block Comicelles of Controlled Length in Aqueous Media

“…38, [49][50][51][52][53][54][55] These developments have also provided access to new building blocks that allow the construction of a variety of complex hierarchical superstructures. [56][57][58][59][60] Herein, in an attempt to tackle the above-mentioned limitations, we report the preparation of well-defined, water-soluble cylindrical micelles of controlled length over a broad range up to 1.10 µm, with the added advantage of having a readily functionalizable coronaforming block.…”

Controlling supramolecular polymerization through multicomponent self‐assembly

“…21,22 Similar to covalent polymers, mechanistic investigations of supramolecular systems have highlighted the need to differentiate between the thermodynamically controlled cooperative nucleation-elongation mechanism, noncooperative isodesmic self-assembly or ringchain equilibria, 8,[23][24][25][26][27][28][29][30] and kinetically controlled self-assembly pathways. 22,[30][31][32][33][34][35][36][37][38][39][40][41][42] However, despite the large advances in elucidating mechanistic details, strategies to rationally manipulate mechanisms and self-assembly pathways in supramolecular polymerization remain scarce. While it is possible to use the toolbox of supramolecular and physical organic chemistry to tune the affinity of a monomer for itself, via molecular design or via concentration and temperature dependent selfassembly, precise engineering of molecular weight, shape, and size of the produced supramolecular polymer remains challenging.…”

Monodisperse Cylindrical Micelles of Controlled Length with a Liquid‐Crystalline Perfluorinated Core by 1D “Self‐Seeding”

“…[5,7] This method has been utilized to prepare complex micelles from a variety of crystallizable BCPs [7c,d,8] and -conjugated amphiphiles. [9,10] In the living CDSA approach, key concepts are borrowed from polymer crystallization field, such as seeded growth and selfseeding. In a self-seeding process, [11] when polymer crystals containing regions with different crystallinity are heated above their apparent melting / dissolution temperatures, crystallites with higher crystallinity survive.…”