TY - JOUR
T1 - Discordant Supramolecular Fibres Reversibly Depolymerised by Temperature and Light
AU - Gerth, Marieke
AU - Berrocal, José Augusto
AU - Bochicchio, Davide
AU - Pavan, Giovanni M.
AU - Voets, Ilja K.
PY - 2021/1/21
Y1 - 2021/1/21
N2 - 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.
AB - 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.
KW - benzene-1,3,5-tricarboxamide
KW - photoisomerisation
KW - photoswitch
KW - responsive
KW - supramolecular polymer
UR - http://www.scopus.com/inward/record.url?scp=85097945870&partnerID=8YFLogxK
U2 - 10.1002/chem.202004115
DO - 10.1002/chem.202004115
M3 - Article
C2 - 33176038
AN - SCOPUS:85097945870
VL - 27
SP - 1829
EP - 1838
JO - Chemistry : A European Journal
JF - Chemistry : A European Journal
SN - 0947-6539
IS - 5
ER -