Synthetic stimuli responsive supramolecular polymers attract increasing interest for their ability to mimic the unique properties of natural assemblies. Here we focus on the well-studied benzene-1,3,5-tricarboxamide (BTA) motif, and substitute it with two (S)-3,7-dimethyloctyl groups and an azobenzene photoswitch. We demonstrate the UV (λ=365 nm) induced depolymerisation of the helical hydrogen-bonded polymers in methylcyclohexane (MCH) through circular dichroism and UV-vis spectroscopy in dilute solution (15 μm), and NMR and iPAINT super-resolution microscopy in concentrated solution (300 μm). The superstructure can be regenerated after thermal depolymerization, whilst repeated depolymerisation can be reversed without degradation by irradiating at λ=455 nm. Molecular dynamics simulations show that the most energetically favourable configuration for these polymers in MCH is a left-handed helical network of hydrogen-bonds between the BTA cores surrounded by two right-handed helices of azobenzenes. The responsiveness to two orthogonal triggers across a broad concentration range holds promise for use in, for example, photo-responsive gelation.
Discordant Supramolecular Fibres Reversibly Depolymerised by Temperature and Light / Gerth, M.; Berrocal, J. A.; Bochicchio, D.; Pavan, G. M.; Voets, I. K.. - In: CHEMISTRY-A EUROPEAN JOURNAL. - ISSN 0947-6539. - 27:5(2021), pp. 1829-1838.
|Titolo:||Discordant Supramolecular Fibres Reversibly Depolymerised by Temperature and Light|
|Data di pubblicazione:||2021|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1002/chem.202004115|
|Appare nelle tipologie:||1.1 Articolo in rivista|