Photochromic Diarylethenes Designed for Surface Deposition: From Self-Assembled Monolayers to Single Molecules

Graphical Abstract

Switching on surfaces: STM studies of diarylethenes are reviewed, and the effect of molecular design on the isomerization and self-assembly processes of these photochromic molecules at the solid-liquid interface at ambient temperature and under low-temperature ultrahigh vacuum conditions are presented. The Review shows how switching may be different under both conditions, and has the goal of providing general molecular design principles that may aid future studies.

Abstract

The efficient switching that can occur between two stable isomers of diarylethenes makes them particularly promising targets for opto- and molecular electronics. To examine these classes of molecules for electronics applications, they have been subjected to a series of scanning tunneling microscopy (STM) experiments, which are the focus of this Review. A brief introduction to the chemical design of diarylethenes in terms of their switching capabilities along with the basics of STM are presented. Next, initial STM studies on these compounds under ambient conditions are discussed. An overview of how molecular design affects the isomerization and self-assembly of diarylethenes at the solid-liquid interface as investigated by STM is then presented, as well as single-molecule studies under ultrahigh vacuum. The last section presents further prospects for molecular design in the field.