Molecular motors with high quantum efficiency and visible-light responsiveness: Meeting two challenges in one design

摘要

The development of light-driven rotary molecular motors is guided by a number of key goals regarding performance and applicability. While a variety of approaches to achieve high quantum yields for small UV-driven motors have been discovered, such as incorporating a protonated or alkylated nitrogen Schiff base, less progress has been made toward the goal to power molecular motors with nondestructive visible light, which will facilitate their future usage in radiation-sensitive environments. Here, we present non-adiabatic molecular dynamics simulations based on multiconfigurational quantum chemistry to demonstrate that Schiff-base motors can maintain high quantum yields also when their conjugated systems are sufficiently large for them to rather be driven by visible light. In particular, we show that a visible-light responsive Schiff-base motor featuring dihydropyridinium and cyclopentenylidene motifs achieves quantum yields of almost 70% for each of the two photoisomerizations that underlie its rotary motion.