Welcome to the Research Group of Henry Dube!


  • Molecular Machines


 Our latest Manuscript

Sunlight Powered kHz Rotation of a Hemithioindigo Based Molecular Motor

is now online with open access at Nature Communications.



Photodriven molecular motors are able to convert light energy into directional motion and hold great promise as miniaturized powering units for future nanomachines. In the current state of the art, considerable efforts have still to be made to increase the efficiency of energy transduction and devise systems that allow operation in ambient and non-damaging conditions with high rates of directional motions. Especially the need for ultraviolet light to induce the motion of virtually all available light-driven motors hampers the broad applicability of these systems. We describe here a hemithioindigo-based molecular motor, which is powered exclusively by nondestructive visible light (up to 500 nm) and rotates completely directionally with kHz frequency at 20 C. This is the fastest directional motion of a synthetic system driven by visible light to date permitting materials and biocompatible irradiation conditions to establish similarly high speeds as natural molecular motors.



  • Photochemistry


Hemithioindigo - an Emerging Photoswitch

Hemithioindigo (HTI) is an emerging photoswitch with many advantageous properties compared to the commonly used photoswitches like azobenzenes, spiropyranes, or dithienylethenes. In this DIGEST the syntheses, physical and photophysical properties of HTI photoswitches and mechanistic explanations for the latter are reviewed. Emphasis will be placed on those distinct properties that render HTIs into unique phototools. Additionally, a broad variety of applications ranging from supramolecular to biological chemistry is presented to highlight the great potential of HTIs as upcoming, alternative photoswitches.

published inTetrahedron Letters (Abstract)

Making Fast Photoswitches Faster - Using Hammett Analysis to Understand the Limit of Donor-Acceptor Approaches for Faster Hemithioindigo Photoswitches


Hemithioindigo (HTI) photoswitches have a tremendous potential for biological and supramolecular applications due to their absorptions in the visible in conjunction with ultrafast photoisomerization and high thermal bistability. Being able to rationally tailor their photophysical properties for a specific application is the key to exploit the full potential of HTIs as photoswitching tools. In this work we used time-resolved absorption spectroscopy and Hammett analysis to discover an unexpected principal limit to the photoisomerization rate for donor substituted HTIs. Using stationary absorption and fluorescence measurements in combination with theoretical investigations, we offer a detailed mechanistic explanation for the observed rate limit. An alternative way of approaching and possibly even exceeding the maximum rate by multiple donor substitution is demonstrated, which gave access to the fastest HTI photoswitch reported to date.

 published in Chemistry - A European JournalAbstract

  • Functional Supramolecular Systems 



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