Fig. 4.
Photoisomerization mechanism. Schematic representation of (A) the photoinduced three-steps (bR∗ → I → CI100 → K) motion [bonds in Å and angles in degrees (in brackets)], (B) the detailed double bicycle-pedal or folding-table motion occurring along the bR∗ → CI100 excited state stage (the variation in the twisting angle—Δ°—for C11═C12, C13═C14, and C15═Nζ is also reported), and (C) the space-saving character of the overall motion (the chromophore ends are at rest during the isomerization process). Structural parameters optimized for the mobile W402 setup are reported in italics when differing from those pertaining to the fixed W402 setup (see Computational Methods and SI Text).