Amphidynamic crystals: Structural blueprints for molecular machines

By considering the relation between molecular structure, molecular dynamics, and phase order, we suggest that certain structures should be able to make up supramolecular assemblies with structurally programmed molecular dynamics. Given that the simplest members of these structures should have the elements required to form a rigid lattice with moving parts, we propose the term amphidynamic crystals to describe them. We also suggest that amphidynamic crystals may form the basis of a new class of molecular machines with a function that is based on the collective dynamics of molecules within crystals. These crystalline molecular machines represent an exciting new branch of crystal engineering and materials science. In this chapter, we described current efforts for the construction of crystalline molecular machines designed to respond collectively to mechanic, electric, magnetic, and photonic stimuli, in order to fulfill specific functions. One of the main challenges in their design and construction derives from the picometric precision required for operation within the close-packed, self-assembled environment of crystalline solids. We illustrate here some of the initial advancements in the preparation, crystallization, and dynamic characterization of these interesting systems.