Taddeucci Andrea, Zinna Francesco, Siligardi Giuliano, Di Bari Lorenzo
Dipartimento di Chimica e Chimica Industriale, University of Pisa, Via Moruzzi 13, 56124 Pisa, Italy.
Diamond Light Source Ltd., Chilton, Didcot OX11 0DE, United Kingdom.
Chem Biomed Imaging. 2023 Jun 9;1(5):471-478. doi: 10.1021/cbmi.3c00049. eCollection 2023 Aug 28.
We introduce an optical microscopy technique, circularly polarized microscopy or CPM, able to afford spatially resolved electronic circular dichroism (ECD) of thin films of chiral organic semiconductors through a commercial microscope equipped with a camera and inexpensive optics. Provided the dichroic ratio is sufficiently large, the spatial resolution is on the order of the μm and is only limited by the magnification optics integrated in the microscope. We apply CPM to thin films of small chiral π-conjugated molecules, which gave rise to ordered aggregates in the thin layer. Primarily, conventional ECD can reveal and characterize chiral supramolecular structures and possible interferences between anisotropic properties of solid samples; however, it cannot generally account for the spatial distribution of such properties. CPM offers a characterization of supramolecular chirality and of commingling polarization anisotropies of the material, describing their local distribution. To validate CPM, we demonstrated that it can be adopted to quantify the local ECD of samples characterized by intense signals, virtually on any standard optical microscope.
我们介绍了一种光学显微镜技术，即圆偏振显微镜（CPM），它能够通过配备相机和廉价光学器件的商用显微镜，获得手性有机半导体薄膜的空间分辨电子圆二色性（ECD）。如果二色比足够大，空间分辨率约为微米级，并且仅受显微镜中集成的放大光学器件的限制。我们将CPM应用于小型手性π共轭分子的薄膜，这些分子在薄层中形成了有序聚集体。传统的ECD主要可以揭示和表征手性超分子结构以及固体样品各向异性性质之间可能存在的干扰；然而，它通常无法说明这些性质的空间分布。CPM能够表征超分子手性以及材料的混合偏振各向异性，并描述它们的局部分布。为了验证CPM，我们证明了它几乎可以在任何标准光学显微镜上用于量化具有强信号的样品的局部ECD。
