Supramolecular polymerization induced by the rotation of light-driven molecular motors

Molecular motors are capable of producing mechanical work on their environment by using their unique capacity to generate non-reciprocal autonomous motions at the nanoscale. Although their operating principles are now well understood, artificial molecular motors have yet to demonstrate their general capacity to confer novel properties on (supra)molecular systems and materials. Here we show that amphiphilic light-driven molecular motors can adsorb onto the air-water interface and form Langmuir monolayers upon compression. Under irradiation, the surface pressure isotherms of these films reveal a drastic shift toward smaller molecular areas as a consequence of their motors’ activation. We explain this counterintuitive phenomenon by the rotation-induced supramolecular polymerization of the amphiphilic motors, limited by the maximal torque they can deliver, and leading to the formation of highly organized patterns. This serendipitous discovery highlights the opportunities offered by molecular motors to control supramolecular polymerization processes and to form active nanostructures for the design of innovative materials.