Supramolecularly directed rotary motion in a photoresponsive receptor

Sander J Wezenberg,Ben L Feringa

doi:10.1038/s41467-018-04249-x

Sander J Wezenberg, Ben L Feringa

Open Access

https://doi.org/10.1038/s41467-018-04249-x

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Journal: Nature Communications	Publication Date: May 18, 2018
Citations: 57	License type: open-access

Affiliation: University of Groningen

Abstract

Stimuli-controlled motion at the molecular level has fascinated chemists already for several decades. Taking inspiration from the myriad of dynamic and machine-like functions in nature, a number of strategies have been developed to control motion in purely synthetic systems. Unidirectional rotary motion, such as is observed in ATP synthase and other motor proteins, remains highly challenging to achieve. Current artificial molecular motor systems rely on intrinsic asymmetry or a specific sequence of chemical transformations. Here, we present an alternative design in which the rotation is directed by a chiral guest molecule, which is able to bind non-covalently to a light-responsive receptor. It is demonstrated that the rotary direction is governed by the guest chirality and hence, can be selected and changed at will. This feature offers unique control of directional rotation and will prove highly important in the further development of molecular machinery.

Highlights

Stimuli-controlled motion at the molecular level has fascinated chemists already for several decades
Density functional theory (DFT) modelling at the B3LYP/6-31G+(d,p) level of theory revealed that the (Z)-isomer adopts a helical conformation as steric crowding causes an out-ofplane distortion, whereas the (E)-isomer has a planar geometry (Supplementary Tables 1–3)
At the photostationary state, where the rates of forward and backward photochemical isomerisation processes are identical given that both isomers absorb light at the irradiation wavelength, a net unidirectional rotation around the central double bond will occur

Summary

Introduction

Stimuli-controlled motion at the molecular level has fascinated chemists already for several decades. By following the principles of light-driven rotary molecular motors[20,21,22] and supramolecular chirality transfer[33,34,35], a chiral guest molecule induces unidirectional rotation around the double bond in a photoswitchable receptor. At the photostationary state, where the rates of forward and backward photochemical isomerisation processes are identical given that both isomers absorb light at the irradiation wavelength, a net unidirectional rotation around the central double bond will occur.

Results

Conclusion