A photoswitch is a type of molecule that can change its structural geometry and chemical properties upon irradiation with electromagnetic radiation. Although often used interchangeably with the term molecular machine, a switch does not perform work upon a change in its shape whereas a machine does.[1] However, photochromic compounds are the necessary building blocks for light driven molecular motors and machines.[2] Upon irradiation with light, photoisomerization about double bonds in the molecule can lead to changes in the cis- or trans- configuration.[3] These photochromic molecules are being considered for a range of applications.