Molecular switches and machines – the tiniest analogues of macroscopic machinery – have the potential to generate enormous impact across multiple scientific and technological applications. This includes, among others, smart materials, soft robotics, energy storage, advanced (molecular) computing, biomedicine and many more. However, this large application scope has only been partially explored. The by far most commonly used energy input to control molecular switches and machines remains light, as it is a convenient source of energy in many applications and can be applied with high spatiotemporal control. This has resulted in the development of numerous photoswitches and light-driven motors and their proof-of-principle applications. In contrast, control of such systems via electrochemical stimulation (i.e. redox) remains much less explored, in spite of its appeal in applications where light may not be an ideal stimulus (for example in opaque environments or at the interface with existing electrical nanotechnologies). This can in part be attributed to the relative lack of redox-active switches that undergo well-defined geometric changes with high reversibility. One such switch is the overcrowded alkene bisthioxanthylidene (BTX), a fatigue-resistant light and redox-responsive multi-state switching scaffold. The objective of this project was to further investigate the fundamental (redox) switching properties of BTX and novel derivatives thereof and to elucidate important design principles of this class of switches. This improved understanding is expected to contribute to the development of the next generation of redox-switches with numerous potential applications such as those listed above.
