Molecular‐Level Devices and Machines

Abstract

The concept of a macroscopic device can be extended to the molecular level by designing and syn- thesizing (supra)molecular species capable of performing specific functions. Molecular- level devices operate via elec- tronic and/or nuclear rear- rangements and, like macro- scopic devices, need energy to operate and signals to com- municate with the operator. The energy needed to make the device work can be sup- plied as chemical energy, elec- trical energy, or light. Among the most useful techniques to monitor the operation of molecular-level devices are spectroscopy (particularly luminescence) and electro- chemistry. A molecular-level electronic set for energy and electron transfer (wires, switches, antennas, plug/ socket, and extension sys- tems) and various kinds of molecular-level machines (tweezers, pyston/cylinder systems, shuttles, systems based on catenanes, rotary motors) have already been synthesized and studied. The extension of the concept of a device to the molecular level is of interest, not only for basic research, but also for the growth of nanoscience and the development of nano- technology. Molecular-level devices should find applica- tions in information storage, display, and processing; in the long run, they are expected to lead to the construction of molecular-based (chemical) computers.