Abstract
With the rise of artificial molecular machines, control of motion on the nanoscale has become a major contemporary research challenge. Tetrathiafulvalenes (TTFs) are one of the most versatile and widely used molecular redox switches to generate and control molecular motion. TTF can easily be implemented as functional unit into molecular and supramolecular structures and can be reversibly oxidized to a stable radical cation or dication. For over 20 years, TTFs have been key building blocks for the construction of redox-switchable mechanically interlocked molecules (MIMs) and their electrochemical operation has been thoroughly investigated. In this review, we provide an introduction into the field of TTF-based MIMs and their applications. A brief historical overview and a selection of important examples from the past until now are given. Furthermore, we will highlight our latest research on TTF-based rotaxanes.
Highlights
The exploration of nature’s molecular machines in the last century led to a paradigm change of how we think about working and organization processes on the molecular level [1,2,3]
We provide an introduction into the field of TTF-based mechanically interlocked molecules (MIMs) and their applications
Oxidation of the solution yields an ambient-stable TTF mixedvalence dimer (12)●+ inside the cage as shown by optical and electrochemical methods. To illustrate how this redox-triggered complexation/decomplexation of pseudorotaxanes is transferred into a controlled molecular motion in MIMs, the TTF-based pseudo[1]rotaxane 12 recently reported by us is shown in Figure 9 [70]
Summary
The exploration of nature’s molecular machines in the last century led to a paradigm change of how we think about working and organization processes on the molecular level [1,2,3]. If this property is changed, the previous conformation of the MIM might become unstable and initiates a molecular motion This simple principle of bistability has been used to create a variety of different switchable TTFbased supramolecular architectures with many versatile applications. The assembly and disassembly of these complexes in solution can be traced by the emergence and fading of these characteristic charge-transfer bands Another outstanding feature of TTFs is that their radical cations can reversibly form cofacial dimers (Figure 3) [34,35,36]. A mixed-valence dimer can be identified by splitting of the first TTF oxidation potential into two distinguishable waves This change in redox behavior can be followed by electrochemical methods such as cyclic voltammetry. The equilibrium between a paramagnetic monomer and a diamagnetic dimer makes the use of electron paramagnetic resonance (EPR) spectroscopy ideal to follow the dimerization process [36]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
