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Updated: Sep 6, 2026

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach
Published on: June 10, 2021
Substitution-driven two-photon absorption modulation on an alternating triphenyamine-vinylpyrimidine series with a
Guillaume Noirbent1, Stephania Abdallah2, Aissa Id Boualim2
1Univ. de Rennes, CNRS, Institut des Sciences Chimiques de Rennes (ISCR), UMR 6226, F-35000 Rennes, Cedex, France. sylvain.achelle@univ-rennes.fr.
Abstract:
A comparative photophysical investigation on the linear and nonlinear properties of twelve alternating triphenylamine-vinylpyrimidine quadrupoles is presented. Within this series, each V-shaped chromophore has been designed with the incorporation of distinctive donor/acceptor substituents which were specifically positioned on the electron donating triphenylamine branches and on the electron withdrawing pyrimidine core. Such structural changes clearly allow a fine regulation of the intramolecular charge transfer (ICT) efficiency within the π-conjugated backbone of the dyes resulting in various electronic effects in terms of transitions energy positioning, excited states dipole moments enhancement, polarity-driven large amplitude fluorescence changes and modulation of the two-photon absorption (2PA) cross-sections with maximum values (δMAX) range from 60 to 430 GM. All these photophysical properties have been methodically described and quantified. Of particular interest, we highlight a limitation in the ICT-driven 2PA amplification by increasing the electron donor ability on triphenylamine subunit. Counterintuitively, such a simple structural change leads to a strong collapse of δMAX by about 70% within our D-π-A-π-D series.
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