title: Unravelling the Pathway Complexity in Conformationally Flexible N-Centered Triarylamine Trisamides.
abstract: Two families of C3-symmetrical triarylamine-trisamides comprising a triphenylamine- or a tri(pyrid-2-yl)amine core are presented. Both families self-assemble in apolar solvents via cooperative hydrogen-bonding interactions into helical supramolecular polymers as evidenced by a combination of spectroscopic measurements, and corroborated by DFT calculations. The introduction of a stereocenter in the side chains biases the helical sense of the supramolecular polymers formed. Compared to other C3-symmetrical compounds, a much richer self-assembly landscape is observed. Temperature-dependent spectroscopy measurements highlight the presence of two self-assembled states of opposite handedness. One state is formed at high temperature from a molecularly dissolved solution via a nucleation-elongation mechanism. The second state is formed below room temperature through a sharp transition from the first assembled state. The change in helicity is proposed to be related to a conformational switch of the triarylamine core due to an equilibrium between a 3:0 and a 2:1 conformation. Thus, within a limited temperature window, a small conformational twist results in an assembled state of opposite helicity.
authors.affiliation: Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, Eindhoven, The Netherlands.|Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, The Netherlands.
authors.forename: Beatrice
authors.initials: B
authors.lastname: Adelizzi
authors.affiliation: Institute of Catalysis, Eindhoven University of Technology, Eindhoven, The Netherlands.
authors.forename: Ivo A W
authors.initials: IAW
authors.lastname: Filot
authors.affiliation: Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, Eindhoven, The Netherlands.|Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, The Netherlands.
authors.forename: Anja R A
authors.initials: ARA
authors.lastname: Palmans
authors.affiliation: Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, Eindhoven, The Netherlands.|Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, The Netherlands.
authors.forename: E W
authors.initials: EW
authors.lastname: Meijer
keywords: CD inversion; handeness inversion; pathway complexity; supramolecular polymerization; triphenylamine