Triazine‐Based Sequence‐Defined Polymers with Side‐Chain Diversity and Backbone–Backbone Interaction Motifs

Abstract

Sequence control in polymers, well‐known in nature, encodes structure and functionality. Here we introduce a new architecture, based on the nucleophilic aromatic substitution chemistry of cyanuric chloride, that creates a new class of sequence‐defined polymers dubbed TZPs. Proof of concept is demonstrated with two synthesized hexamers, having neutral and ionizable side chains. Molecular dynamics simulations show backbone–backbone interactions, including H‐bonding motifs and pi–pi interactions. This architecture is arguably biomimetic while differing from sequence‐defined polymers having peptide bonds. The synthetic methodology supports the structural diversity of side chains known in peptides, as well as backbone–backbone hydrogen‐bonding motifs, and will thus enable new macromolecules and materials with useful functions.

Recent Progress in the Design of Monodisperse, Sequence-Defined Macromolecules

“…The obtained monodisperse oligomers, as well as the monomers, were carefully characterized by proton and carbon NMR, HRMS and HPLC. HPLC chromatograms and mass spectra thereby prove the high purity of the products …”

“…Due to this deactivation of the cyanuric chloride, which serves as a building block, the approach does not require any protecting groups. Different mono‐substituted cyanuric chloride submonomers were synthesized in a one‐step procedure in high yields (between 76 and 91%, depending on the substituent) and incorporated into the oligomeric backbone . By molecular dynamics simulations, it could be shown that triazine‐based polymers exhibit backbone interactions, such as π–π ‐interactions or hydrogen bonding.…”

“…By molecular dynamics simulations, it could be shown that triazine‐based polymers exhibit backbone interactions, such as π–π ‐interactions or hydrogen bonding. These properties might be interesting in terms of intermolecular self‐assembly and the formation of three‐dimensional structures . The synthesis of sequence‐defined hexamers was demonstrated in good overall yields.…”

“…By reacting the cyanuric chloride compound, the substrate is getting deactivated and elevated temperatures are necessary to conduct further reactions, avoiding protecting groups. The approach yields well‐defined oligomers in high purity and good overall yields …”

Orthogonal Click Postfunctionalization of Alternating Copolymers Prepared by Nitroxide‐Mediated Polymerization

“…Recently, valuable advances have been made in the field of sequence‐controlled polymerization. Iterative multi‐step approaches provide excellent sequence‐fidelity but are tedious to conduct and therefore limited to oligomers and smaller polymeric chains . Template‐based strategies, polymerizations based on multicomponent reactions, and the polymerization of sequence‐controlled precursors allow for higher molecular weights but are limited to relatively simple repetitive patterns.…”