Liquid-Assisted One-Pot Mechanosynthesis and Properties of Neutral Donor-Acceptor [2]Rotaxanes.

An efficient liquid-assisted one-pot two-step synthesis of neutral donor-acceptor [2]rotaxanes has been successfully realized under high-speed vibration milling conditions, by taking advantage of the donor-acceptor interaction between the electron-rich naphthalene unit of a macrocyclic polyether and the electron-deficient naphthalene diimide unit of a thread component for the threading process and click reaction as the stoppering process. The present method provides a powerful, fast, and environmentally benign alternative to traditional solvent-based approaches due to its notable advantages such as very small amount of solvent, no external heating, shorter reaction time, and higher yield. In addition, the charge-transfer interaction and electrochemically induced shuttling of the synthesized neutral donor-acceptor [2]rotaxanes have been demonstrated.