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Two‐Photon Initiating Efficiency of a Ditopic Alkoxynitrostilbene Reacting through a Self‐Regenerative Mechanism
Author(s) -
Hobeika Nelly,
Chaumeil Helene,
Mhanna Rana,
Jin Ming,
Wu Xingyu,
Spangenberg Arnaud,
Versace DavyLouis,
MorletSavary Fabrice,
Malval JeanPierre
Publication year - 2020
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.202000437
Subject(s) - photoinitiator , chromophore , photochemistry , chemistry , absorption (acoustics) , amine gas treating , polymerization , two photon absorption , materials science , organic chemistry , monomer , laser , polymer , optics , physics , composite material
The photophysical properties and the photoinitiating reactivity of a ditopic alkoxynitrostilbene were compared to those of its single branch chromophore used as a reference. Whereas a trivial additive effect is observed when considering the one‐ and two‐photon absorption properties, a clear and very significant amplification has been highlighted for the photoreactivity of this free radical photoinitiator which was used as a hydrogen abstractor in presence of an aliphatic amine co‐reactant. We indeed demonstrate that the proximity of two nitroaromatics moieties within the same molecular architecture gives rise to an original cycling mechanism based on a stepwise photo triggering of each photoredox center followed by a subsequent regenerative process. The combination of a high two‐photon absorption cross‐section (δ 780nm ≈330 GM) with a strong enhancement in photoreactivity makes this nitrostilbene bichromophore a very suitable candidate for two‐photon polymerization applications.