Light-driven molecular machines offer tremendous opportunities in the development of systems that can be operated with spatiotemporal precision at the nanoscale. Among these so called photoactuators, two main classes of compounds emerge. The former are the molecular photoswitches, systems able to interconvert between two (or more) states by the action of light (or thermal) stimuli. Light allows these molecules to escape microscopic reversibility and populate a metastable state, whose steric and electronic properties differ from the starting, stable, form. The main characteristic of photoswitches is the stochastic nature of their motion in the interconversion between one state and the other. On the other hand, photochemically-driven molecular motors based on overcrowded alkenes introduce point and helical chirality in their core structure and can perform a fully unidirectional 360° rotation about their axle, which is normally composed by a C=C double bond.
Understanding and applying the same concepts that drive the unidirectionality of molecular photoactuators at the ground and at the excited state is a fundamental challenge in order to design novel, more efficient chemical structures that can be addressed by light, that can be applied in the context of smart materials, soft robotics and photopharmacology.
Consequently, the goal of the action was to study the principles and processes that are at the basis of the chiral information transfer in supramolecular structures containing photoswitches and molecular motors, both to impart unidirectionality to otherwise achiral photochemical switches by means of external interactions with the chiral environment, and to exploit the chiral nature of the molecular motors to affect an (a)chiral environment.
