Light-driven open-close motion of chiral molecular scissors

The first example of "light-driven chiral molecular scissors" (1), which consists of 1,1-,3,3-tetraarylferrocene as a pivot part and azobenzene as a driving part, was synthesized. Absorption, circular dichroism (CD), and 1H NMR spectral studies on the photoinduced isomerization process of an enantiomer of 1 agreed well with a prediction by a DFT calculation, where a motion of the handles via light-driven contraction/expansion of the connecting azobenzene strap was transformed, through a pivotal motion of the ferrocene unit, into an open-close motion of the blade parts.