Covalently Trapped Triarylamine-Based Supramolecular Polymers

Chemistry. 2019 Nov 13;25(63):14341-14348. doi: 10.1002/chem.201902404. Epub 2019 Oct 15.

Abstract

C3 -Symmetric triarylamine trisamides (TATAs), decorated with three norbornene end groups, undergo supramolecular polymerization and further gelation by π-π stacking and hydrogen bonding of their TATA cores. By using subsequent ring-opening metathesis polymerization, these physical gels are permanently crosslinked into chemical gels. Detailed comparisons of the supramolecular stacks in solution, in the physical gel, and in the chemical gel states, are performed by optical spectroscopies, electronic spectroscopies, atomic force microscopy, electronic paramagnetic resonance spectroscopy, X-ray scattering, electronic transport measurements, and rheology. The results presented here clearly evidence that the core structure of the functional supramolecular polymers can be precisely retained during the covalent capture whereas the mechanical properties of the gels are concomitantly improved, with an increase of their storage modulus by two orders of magnitude.

Keywords: ROMP; gels; rheology; supramolecular polymers; triarylamines.