Klausen Maxime, Dubois Victor, Clermont Guillaume, Tonnelé Claire, Castet Frédéric, Blanchard-Desce Mireille
Univ. Bordeaux , Institut des Sciences Moléculaires (UMR5255 CNRS) , 351 cours de la Libération , F-33405 , Talence , France . Email:
Chem Sci. 2019 Mar 13;10(15):4209-4219. doi: 10.1039/c9sc00148d. eCollection 2019 Apr 21.
Photolabile protecting groups (PPGs) releasing bioactive compounds upon two-photon excitation have emerged as increasingly popular tools to control and study physiological processes. Yet the limited two-photon photosensitivity of many cages is still a critical issue for applications. We herein report the design, synthesis and photophysical study of polarized extended coumarinyl derivatives which show large two-photon sensitivity (up to 440 GM) at two complementary wavelengths in the NIR spectral range. DFT calculations demonstrate that subtle tuning of polarization in the ground-state and confinement of the photo-induced intramolecular charge transfer upon excitation is responsible for enhancing two-photon absorption while maintaining large uncaging efficiency. These findings open a new engineering route towards efficient coumarinyl PPGs.
在双光子激发时释放生物活性化合物的光不稳定保护基团（PPGs）已成为控制和研究生理过程越来越受欢迎的工具。然而，许多笼形化合物有限的双光子光敏性仍是应用中的一个关键问题。我们在此报告了极化扩展香豆素基衍生物的设计、合成及光物理研究，这些衍生物在近红外光谱范围内的两个互补波长处显示出大的双光子敏感性（高达440 GM）。密度泛函理论计算表明，基态极化的细微调节以及激发时光诱导分子内电荷转移的限制是增强双光子吸收同时保持大的解笼效率的原因。这些发现为高效香豆素基PPGs开辟了一条新的工程路线。
