Design and photoisomerization dynamics of a new family of synthetic 2-stroke light driven molecular rotary motors.

A new family of light driven molecular rotary motors, which can be synthesized from easily available precursor compounds and which are capable of completing a full 360° revolution by two photoisomerization steps only, is proposed. The non-adiabatic molecular dynamic simulations show that the photoisomerization steps of the motor's working cycle occur on an ultrafast time scale (ca. 200-300 fs), have a very high quantum yield of isomerization (0.91-0.97), and display high selectivity of torsion in the same direction. It is expected that the new motor should remain operational at lower temperatures than the currently existing motors.