Photomechanical Crystals Made from Anthracene Derivatives

Some anthracene derivatives can transform photons into molecular-scale motions by undergoing photochemical reactions. Grown into nano- or microcrystals, these derivatives can amplify molecular-scale motions to produce actuation on much larger length scales. In this chapter, we describe the basic principles of photomechanical materials based on molecular crystals in general and anthracene derivatives in particular. We then focus on specific anthracene derivatives that were thoroughly studied by us and describe their photomechanical behavior with an emphasis on the importance of molecular packing, crystal shape, and illumination conditions. Finally, we identify areas for future research, ranging from an improved understanding of solid-state photochemistry and photophysics to improving molecule and crystal design to interfacing these photoactive molecular crystals with other materials.