Indane Based Molecular Motors: UV-Switching Increases Number of Isomers.

We describe azophenylindane based molecular motors (aphin-switches) which have two different rotamers of trans -configuration and four different rotamers of cis -configuration. The behaviors of these motors were investigated both experimentally and computationally. The conversion of aphin-switch does not yield single isomer but a mixture of these. Although the trans to cis conversion leads to the increase of the system entropy some of the cis -rotamers can directly convert to each other while others should convert via trans -configuration. The motion of aphin-switches resembles the work of a mixing machine with indane group serving as a base and phenol group serving as a beater. The aphin-switches presented herein may provide a basis for promising applications in advanced biological systems or particularly in cases where on demand disordering of molecular packing has value, such as lipid bilayers.