A Chemically Driven Rotary Molecular Motor Based on Reversible Lactone Formation with Perfect Unidirectionality

Among the amazing variety of ingenious molecular machines present in living organisms, enabling motility, responsiveness, and out-of-equilibrium behavior among others, rotary motors, such as the ATPase and bacterial flagellar motors, hold a special position. While these biological machines are mainly powered by chemical conversion and artificial light-driven rotary molecular motors have been well established, genuine chemically driven rotary motor systems are very limited. Here, we report a chemically powered rotary molecular motor based on biaryl structures that allows complete 360° unidirectional rotation i.e., >99% based on simple esterification chemistry. All the stereoisomers involved in the 4-stage rotary process have been characterized using X-ray crystallography confirming the relative stereochemistry of each isomer in accordance with the sequential and complete stereoselective operation of the rotary system. Having established the basic principles of this novel molecular rotary motor, it will facilitate the design of more sophisticated future artificial machine systems driven solely by chemical energy.