Fig. 1. (a) CD and UV-vis spectra of PAzo-l/d-3 in THF. (b) CD and UV-vis spectra of PAzo-l-3 in DCE/MCH mixed solvents with different volume ratios. (c) Plots of CD and UV-vis absorption intensity values at 364 nm with the concentration of PAzo-l-3 in THF at 20 °C. (d) The IR and VCD spectra of PAzo-l/d-3 in THF-d₈. (e) CD and UV-vis spectra of PAzo-l-3 in dissolution (DCE), in assembly (DCE/MCH = 0.6/2.4, v/v) and after heating–cooling (H–C) treatment. (f) The chiroptical switch with triple transitions. The steps of the operation are first dissolution (−) and then assembly at room temperature (+), followed by heating–cooling (−) of PAzo-l-3. (g) The molecular packing and macromolecular geometry in dissolved and aggregated states, respectively.