Living supramolecular polymerization of fluorinated cyclohexanes

Giovanni M. Pavan,Max von Delius,Ute Kaiser,Oleksandr Shyshov,Andrea Gardin,Haoyuan Qi,Davide Bochicchio,Shyamkumar Vadakket Haridas,Luca Pesce

doi:10.1038/s41467-021-23370-y

Abstract

The development of powerful methods for living covalent polymerization has been a key driver of progress in organic materials science. While there have been remarkable reports on living supramolecular polymerization recently, the scope of monomers is still narrow and a simple solution to the problem is elusive. Here we report a minimalistic molecular platform for living supramolecular polymerization that is based on the unique structure of all-cis 1,2,3,4,5,6-hexafluorocyclohexane, the most polar aliphatic compound reported to date. We use this large dipole moment (6.2 Debye) not only to thermodynamically drive the self-assembly of supramolecular polymers, but also to generate kinetically trapped monomeric states. Upon addition of well-defined seeds, we observed that the dormant monomers engage in a kinetically controlled supramolecular polymerization. The obtained nanofibers have an unusual double helical structure and their length can be controlled by the ratio between seeds and monomers. The successful preparation of supramolecular block copolymers demonstrates the versatility of the approach.

Highlights

The development of powerful methods for living covalent polymerization has been a key driver of progress in organic materials science
Many recent examples of living supramolecular polymerization (LSP) are based on a similar use of offpathway aggregates[14], which can be self-assembled from diverse building blocks such as rylene dyes15–21,BODIPY dyes[22,23], N-heteroangulenes[24] and amphiphilic PtII complexes[25]
Theoretical studies predict a large and cooperative enhancement of the dipole moment during aggregation of all-cis C6H6F6 into one-dimensional stacks[55]. We wondered whether this cooperativity could be used to drive the formation of thermodynamically stable supramolecular polymers, while the large dipole moment of all-cis C6H6F6 (6.2 Debye) could lead to folded, metastable states that would allow us to perform LSP

Summary

Introduction

The development of powerful methods for living covalent polymerization has been a key driver of progress in organic materials science. No evidence for supramolecular aggregates was observed when an analogous study was carried out with reference compounds Ref[2] (conventional cyclohexane) and MeM3 (methylated amide), indicating that both the all-cis C6H6F5 motif and the amide bond are crucial for supramolecular polymerization (Supplementary Fig. 9).

Results

Conclusion