Obstarczyk Patryk, Kazan Rania, Bürgi Thomas, Samoć Marek, Olesiak-Bańska Joanna
Institute of Advanced Materials, Wroclaw University of Science and Technology, Wybrzeże Stanisława Wyspiańskiego 27, Wrocław 50-344, Poland.
Département de Chimie Physique, Université de Genève, 30 Quai Ernest Ansermet, CH-1211 Genève 4, Geneva,Switzerland.
J Am Chem Soc. 2024 Dec 25;146(51):35011-35015. doi: 10.1021/jacs.4c12321. Epub 2024 Dec 10.
While circular dichroism (CD) and optical activity (OA) are well established as optical effects used in characterization of chiral media, harmonic generation and multiphoton circular dichroism are increasingly seen as new, convenient ways of exploring chirality thanks to their operation in the near-infrared range of wavelengths. However, quantitative data about two-photon circular dichroism (2PCD) of organic and inorganic materials are scarce, and even less can be found about three-photon circular dichroism (3PCD). Here, we show that both 2PCD and 3PCD can be readily detected in chiral atomically precise gold nanoclusters via polarimetric Z-scan technique. We provide quantitative data on 2PCD and 3PCD of both enantiomers of Au(PET) nanoclusters, which exhibit extraordinary chiroptical properties arising from the interplay of several levels of molecular organization. Interestingly, the corresponding two- and three-photon dissymmetry factors of Au(PET) enantiomers are significantly enhanced in comparison to the one-photon CD by factors of 178 and 217, respectively.
虽然圆二色性（CD）和旋光性（OA）作为用于手性介质表征的光学效应已得到充分确立，但由于谐波产生和多光子圆二色性在近红外波长范围内起作用，它们越来越被视为探索手性的新的便捷方法。然而，关于有机和无机材料的双光子圆二色性（2PCD）的定量数据很少，关于三光子圆二色性（3PCD）的数据更是少之又少。在此，我们表明通过偏振Z扫描技术可以在手性原子精确的金纳米团簇中轻松检测到2PCD和3PCD。我们提供了Au（PET）纳米团簇两种对映体的2PCD和3PCD的定量数据，这些纳米团簇由于几个分子组织水平的相互作用而表现出非凡的手性光学性质。有趣的是，与单光子CD相比，Au（PET）对映体相应的双光子和三光子不对称因子分别显著增强了178倍和217倍。
