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Updated: Mar 3, 2026

Determination of the Photoisomerization Quantum Yield of a Hydrazone Photoswitch
Published on: February 7, 2022
Enhanced photo-responsiveness in a photoswitchable system model: emergent hormetic catalysis
1Laboratoire des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex 9, France.
Abstract:
Michaelis Menten catalysis by a T-photochromic system has been analyzed numerically. Using an appropriate set of rate constants and quantum yields, we have evidenced an enhanced photo-responsiveness at a medium light intensity: the plot of the initial rate vs. light intensity is bell-shaped. This emergent phenomenon can be qualified as hormetic catalysis. The analysis of the chemical flows shows that a directional rotation occurs within the cyclic scheme. Non equilibrium conditions are provided by two independent sources: the chemical energy dissipation from the irreversible exergonic reaction and the steady transformation of light into heat by T-photochromism. A literature survey, showing that most of the required kinetic features are not so rare, let us anticipate its practical feasibility.
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