Spiropyran-merocyanine photochromic structural transformation studied in-situ in single-Micro/Nanocrystals by Electron Diffraction
UC Los Angeles
Characterization and Properties
Synthesis and Formulation
Spiropyrans (SP) are among the most well-known photoswitches. When irradiated with UV light, the C-O bond in a pyran ring breaks, leading to merocyanine (MC) formation. This transformation leads to strong photochromism, causing a color change (e.g. from colorless to red or from yellow to purple). Due to this phenomenon, spiropyrans can be used as optical materials for various applications, such as optical memories or photosensors. In order to understand the photochromism of functionalized spiropyrans in confined spaces (in crystals or in polymeric matrices), a deep insight into the atomic-level structure of spiropyrans is required. This can be achieved through microcrystal Electron Diffraction (μ-ED), which allows us to determine the structures of spiropyrans from extremely small crystals that are not visible to the naked eye. This will enable us to understand and design modern spiropyran-based materials.