Molecular motor powered by light alone

Chemists have developed the first molecular motor that can be powered by just light, irrespective of temperature.

Ludwig-Maximilians-Universitaet’s Henry Dube and student Aaron Gerwien developed the motor, or chemical carousel, which even rotates faster at lower temperatures.

“We have succeeded in modifying the molecule such that a complete rotation of one of the structural modules relative to the other requires only three reaction steps,” Dube said. “Each rotation step is made up of three different photoreactions, two of which we experimentally demonstrated directly for the first time only this year.”

The new motor is based on an organic substance called hemithioindigo, made up of two different carbon skeletons, connected by a mobile double bond. The LMU team said all three steps involved in the full rotation are promoted by a reduction in temperature.

Dube and Gerwien believe their motor’s driving mechanism will make it possible for researchers to synthesise molecular machines enabling new, unique applications.

Molecular motors, which rotate in a single direction in response to an external energy output, constitute an important class of components for future applications in nanotechnology. So far, light-driven molecular motors have been dependent on reactions that require heat and so rely on a minimum environmental temperature.

LMU had its findings published in the Journal of the American Chemical Society.