SKYFALL · Stimuli-responsive chiral foldamers in solution and light-emitting diodes

Stimuli-responsive CHiral FOldamers in solution and Light-emitting diodes (SKYFALL) will extend the frontier of supramolecular and materials chemistry through (i) the synthesis of helical fluorescent (photo) responsive foldamers, (ii) identifying the physico-chemical parameters governing the single or multiple helical state and assessing their impact on (chir)optical properties and (iii) incorporating the most promising chiral fluorescent foldamers into CP-OLEDs. Stereogenic centres will be introduced to the foldamer backbone to control its helicity, generating a chiral environment for the fluorophores allowing for circularly polarised luminescence (CPL). Fluorophores with a broad range of emission profiles and electron donating and accepting capabilities will be grafted to the foldamer backbone through reliable Cu-Assisted alkyne-azide cycloadditions (CuAACs). A photoswitch will also be incorporated to a series of foldamers generating opportunities to control hybridisation through their response to light irradiation in addition to temperature, concentration and solvophobic effects. The hybridisation capabilities of these foldamers will be assessed and the equilibria between single- and double-stranded helices (homoduplexes) will be determined under the aforementioned parameters. Donor-acceptor interactions of the appended fluorophores will be exploited to also target heteroduplexes. Synthesising such supramolecular structures constitutes a leap forward in the field of foldamers and more generally supramolecular chemistry, providing an innovative strategy to reach CPL in the visible range. The effect of these hybridisation states on the chiroptical properties will, therefore, be studied in solution and solid-state (thin films). The foldamer hybridisation states that exhibit the greatest dissymmetry values and quantum yields in the solid-state will be incorporated into CP-OLED devices.