Molecular machines:from photoresponsive molecules to dynamic materials

Molecular machines are synthetic small molecules that could utilize their mechanical movement triggered by external stimuli to accomplish useful tasks. Since the development of molecular machines towards various applications, the efficiency and robustness of these systems are considered to be of great importance and still somehow very challenging. To some extent, the use of short wavelengths of harmful UV light, low photoefficiency (quantum yield of photoisomerization) as well as low PSD, are limiting the practical application of these photoresponsive systems. Thus, to realize high spatiotemporal control over dynamic properties with large windows of non-invasive operation, the design of new molecular tools in addition to boosting the performance of established molecular motors and switches is a vital challenge to improve the next generation of molecular machines. This dissertation is focused on two of photoresponsive molecular machines, i.e., molecular motors and switches, by taking advantage of their unique properties to control specific functions. The first three research chapters (chapter 2 to chapter 4) are mainly devoted to boosting the performance of light-driven molecular motors and switches by molecular engineering, while the following four chapters are dedicated to controlling molecular motion of light-responsive switches in porous solids or supramolecular systems