Strategies towards designing visible and near-infrared light driven molecular motors

Light is one of the most powerful and versatile stimuli for controlling molecular motion, serving as a key driving force in the development of photoresponsive molecular systems. Among these architectures, artificial molecular motors represent a unique class of molecules capable of converting light energy into chirality-controlled unidirectional rotary motion. However, the majority of reported examples are operated under ultraviolet excitation, which restricts their practical applicability especially in biomolecular systems and sensitive responsive materials. To address these limitations, major recent effort has been devoted to extending photoresponsiveness of molecular motors into the visible and near-infrared (NIR) regions which enables milder and more efficient operation. This review summarizes the principal molecular design strategies that have been developed to achieve such red-shifted photoactivation of molecular motors. Moreover, we highlight the current challenges and outline future directions toward the realization of high-efficiency, multifunctional, and programmable visible/NIR-light-driven molecular motors for integration into responsive materials, catalysis, and biological systems.