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.

中文翻译：

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通过自生机理反应的双位烷氧基硝基二苯乙烯的双光子引发效率。

比较了对位烷氧基硝基二苯乙烯与其单支生色团的光物理性质和光引发反应性，并将其用作参考。考虑到单光子吸收特性和双光子吸收特性时，观察到微不足道的加性效应，该自由基光引发剂的光反应性在脂肪族胺化合物存在下用作氢提取剂的光反应性得到了明显且非常显着的放大。反应物。我们确实证明了在相同分子结构内两个硝基芳族基团的接近性产生了基于每个光氧化还原中心的逐步光触发并随后的再生过程的原始循环机制。高双光子吸收截面（_{δ780nm）的组合}≈330GM）的光反应性大大增强，使得这种亚硝基二苯乙烯双发色团非常适合用于双光子聚合应用。