Figure 4.

Photochemical and thermal isomerization of motor 1.(a) Sample of (Z_SZ_S)-1 irradiated to PSS with 455 nm light at −85 °C. The sample was subsequently kept at −85 °C for 45 min and warmed up to room temperature. The proposed mechanism with determined rate constants and occurring processes highlighted (bottom). (b) Thermal decay of pre-irradiated (Z_SZ_S)-1 (PSS with 455 nm light at −85 °C) at −70 °C. The sample was subsequently warmed up to room temperature. Proposed mechanism with determined rate constants and occurring processes highlighted (bottom). (c) Corresponding ¹⁹F NMR spectra (470 MHz, 5 mM in CD₂Cl₂) of (Z_SZ_S)-1 upon irradiation and after partial and full relaxation.