Controlling the length of porphyrin supramolecular polymers via coupled equilibria and dilution-induced supramolecular polymerization

Elisabeth Weyandt; Luigi Leanza; Riccardo Capelli; Giovanni M Pavan; Ghislaine Vantomme; E W Meijer

doi:10.1038/s41467-021-27831-2

Controlling the length of porphyrin supramolecular polymers via coupled equilibria and dilution-induced supramolecular polymerization

Nat Commun. 2022 Jan 11;13(1):248. doi: 10.1038/s41467-021-27831-2.

Authors

Elisabeth Weyandt^{1

2}, Luigi Leanza³, Riccardo Capelli³, Giovanni M Pavan^{3

4}, Ghislaine Vantomme^{1

2}, E W Meijer^{5

6}

Affiliations

¹ Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600, Eindhoven, MB, The Netherlands.
² Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, P.O. Box 513, 5600, Eindhoven, MB, The Netherlands.
³ Department of Applied Science and Technology, Politecnico di Torino, 10129, Torino, Italy.
⁴ Department of Innovative Technologies, University of Applied Sciences and Arts of Southern Switzerland, 6962, Lugano-Viganello, Switzerland.
⁵ Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600, Eindhoven, MB, The Netherlands. e.w.meijer@tue.nl.
⁶ Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, P.O. Box 513, 5600, Eindhoven, MB, The Netherlands. e.w.meijer@tue.nl.

Abstract

Multi-component systems often display convoluted behavior, pathway complexity and coupled equilibria. In recent years, several ways to control complex systems by manipulating the subtle balances of interaction energies between the individual components have been explored and thereby shifting the equilibrium between different aggregate states. Here we show the enantioselective chain-capping and dilution-induced supramolecular polymerization with a Zn²⁺-porphyrin-based supramolecular system when going from long, highly cooperative supramolecular polymers to short, disordered aggregates by adding a monotopic Mn³⁺-porphyrin monomer. When mixing the zinc and manganese centered monomers, the Mn³⁺-porphyrins act as chain-cappers for Zn²⁺-porphyrin supramolecular polymers, effectively hindering growth of the copolymer and reducing the length. Upon dilution, the interaction between chain-capper and monomers weakens as the equilibria shift and long supramolecular polymers form again. This dynamic modulation of aggregate morphology and length is achieved through enantioselectivity in the aggregation pathways and concentration-sensitive equilibria. All-atom and coarse-grained molecular simulations provide further insights into the mixing of the species and their exchange dynamics. Our combined experimental and theoretical approach allows for precise control of molecular self-assembly and chiral discrimination in complex systems.