Light to investigate (read) and operate (write) molecular devices and machines

Abstract

Functional supramolecular systems can exploit photoinduced processes for gaining energy as well as for providing information on their state. We discuss the operation of these species from a fundamental viewpoint and we illustrate their potential to function as nanoscale devices and machines by means of selected examples.

Halogen-Bonded Photoresponsive Materials

“…Concerning functional materials, the power of azobenzene lies in the chemical stability of the moiety even after prolonged switching and in the possibility for the molecular-scale photoisomerization to give rise to a cascade of motions beyond the size scale of an individual molecule, eventually emerging as macroscopic motions. Therefore, azobenzene photoswitching is equally useful in both molecular machinery/electronics [15,16] and macroscopic actuation [17,18]. Herein, four types of photoinduced motions deserve special attention, namely photoalignment (Fig.…”

Switchable molecule-based materials for micro- and nanoscale actuating applications: Achievements and prospects

“…Another important point we must mention at the beginning is that the exciting and also very challenging field of single molecule machines is not covered by the present review, the interested reader can find details on this approach in Refs. [6][7][8][9][10][11][12]. Here we focus on materials based on molecular switches.…”

Drug Delivery by Controlling a Supramolecular Host–Guest Assembly with a Reversible Photoswitch

“…The assembly and disassembly of host–guest complexes by means of the application of external stimuli is an elegant exercise of functional supramolecular chemistry that builds on the reversibility of non‐covalent interactions . This has led to viable approaches towards intelligent supramolecular materials, molecular information processing, the release/capture of compounds in bio‐inspired applications, and drug‐delivery systems . Among other stimuli, such as chemical and electrochemical signals, the use of light has been a preferred choice due to the possibility of conducting spatiotemporally and remotely controlled experiments .…”