Second-Generation Light-Fueled Supramolecular Pump

Abstract

We describe the modular design of a pseudorotaxane-based supramolecular pump and its photochemically driven autonomous nonequilibrium operation in a dissipative regime. These properties derive from careful engineering of the energy maxima and minima along the threading coordinate and their light-triggered modulation. Unlike its precursor, this second-generation system is amenable to functionalization for integration into more complex devices.

Distinctive features and challenges in catenane chemistry

“…Co-conformational switching in catenanes and rotaxanes has in fact been widely recognised as an efficient mechanism for developing molecular switches and machines. 12,13 When two or more recognition sites are incorporated in a catenane or rotaxane, switching between several stable co-conformers can be achieved by applying a specific stimulus. Both the population and switching rate of the co-conformers will be critical to the performance of the molecular switches and machines.…”

Photochemical Energy Conversion with Artificial Molecular Machines

“…More recently, the same behavior was observed with modified ring and axle components, provided that the key mechanistic elements depicted in Figure 7 b are preserved. 91 − 94 These results highlight the robustness and flexibility of this approach, whose appeal is further increased by its minimalist design, structural simplicity of the components, ease of preparation, stability, and reversibility.…”

“…Indeed, the continuous irradiation at appropriate wavelengths (280–350 nm) of 5 at a sufficiently high temperature (60 °C) results in repeated rotations, and thus, the motor can operate autonomously under the supply of light energy. 94 …”

Real-time observation of the dynamics of an individual rotaxane molecular shuttle using a single-molecule junction

“…The [2]rotaxane-based molecular shuttle 1 is based on the well-established [37][38][39][40][41][42][43][44][45][46][47][48] crown-ether-dibenzylammonium-triazolium system. The axle was designed to have two principal binding sites for the crown ether, namely, a dibenzylammonium motif (DBA) and a methyl triazolium group (MTA).…”