Kumar Pravesh, Bala Indu, De Ritobrata, Kumar Pal Santanu, Venkataramani Sugumar
Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali Sector 81, SAS Nagar, Knowledge City Manauli, 140306, Punjab, India.
Chemistry. 2023 Jan 12;29(3):e202202876. doi: 10.1002/chem.202202876. Epub 2022 Nov 22.
Three benzene-1,3,5-tricarboxamide (BTA) core-based molecular systems appended with phenylazo-3,5-dimethylisoxazole photoswitches at the peripheral position through variable-length alkoxy chains have been designed and synthesized. The supramolecular interactions of the mesogens provided discotic nematic liquid crystalline assembly as confirmed by polarized optical microscopy (POM) and X-ray diffraction (XRD) studies. Spectroscopic studies confirmed the reversible photoswitching and excellent thermal stability of the photoswitched states in solution phase and thin film. Also, atomic force microscopic (AFM) and POM investigations demonstrated the morphological changes in the self-assembly induced by the photoirradiation as monitored by the changes in the height profiles and optical appearance of the textures, respectively. Remarkably, the liquid crystalline discotic molecules showed reversible "on and off states" controlled by light at ambient temperature.
设计并合成了三种基于苯-1,3,5-三甲酰胺（BTA）核心的分子体系，这些体系通过可变长度的烷氧基链在外围位置连接了苯基偶氮-3,5-二甲基异恶唑光开关。通过偏光显微镜（POM）和X射线衍射（XRD）研究证实，介晶的超分子相互作用提供了盘状向列液晶组装体。光谱研究证实了光开关状态在溶液相和薄膜中的可逆光开关特性以及优异的热稳定性。此外，原子力显微镜（AFM）和POM研究分别通过纹理高度轮廓和光学外观的变化，证明了光照射引起的自组装形态变化。值得注意的是，液晶盘状分子在环境温度下表现出受光控制的可逆“开和关状态”。
