Hu Chenhui, Li Huimin, Xu Guangsheng, Yang Zhihua, Han Jian, Pan Shilie
Research Center for Crystal Materials, State Key Laboratory of Functional Materials and Devices for Special Environmental Conditions, Xinjiang Key Laboratory of Functional Crystal Materials, Xinjiang Technical Institute of Physics and Chemistry, CAS, 40-1 South Beijing Road, Urumqi 830011, China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
ACS Cent Sci. 2024 Nov 27;10(12):2312-2320. doi: 10.1021/acscentsci.4c01401. eCollection 2024 Dec 25.
For non-π-conjugated [SO] units, it is challenging to generate sufficient birefringence, owing to the high symmetry of the regular tetrahedron. Unlike the traditional trial-and-error approach, we propose a new paradigm for birefringence engineering to tune the optical properties based on [SO] units. Through the strategy of ligand substitution, we can predict its effect on the band gap and anisotropy. Theoretical evaluations reveal generalized results that the anisotropic electron distribution of new functional groups induced by the suitable ligand substitution contributes to the band gap and birefringence. To further validate the correctness of the paradigm, we experimentally synthesized and characterized nine novel compounds with selected functional modules. By the new paradigm of ligand substitution, they can reach up to 4-6 times the birefringence of the corresponding sulfate and maintain the wide bandgap. Through rational design, (CNH)SONH exhibits about 35 times the birefringence of LiSO, which is a significant order of magnitude improvement and verifies the superiority of our proposed paradigm. This work provides a new paradigm for the modification to the non-π-conjugated group and will guide and accelerate the exploration of novel birefringent crystals in the short-wavelength region.
对于非π共轭的[SO]单元，由于正四面体的高度对称性，要产生足够的双折射具有挑战性。与传统的试错方法不同，我们提出了一种基于[SO]单元的双折射工程新范式，用于调节光学性质。通过配体取代策略，我们可以预测其对带隙和各向异性的影响。理论评估揭示了一般化的结果，即合适的配体取代诱导的新官能团的各向异性电子分布有助于带隙和双折射。为了进一步验证该范式的正确性，我们通过实验合成并表征了九种具有选定功能模块的新型化合物。通过配体取代的新范式，它们的双折射可达相应硫酸盐的4至6倍，并保持宽带隙。通过合理设计，(CNH)SONH的双折射约为LiSO的35倍，这是一个显著的数量级改进，并验证了我们提出的范式的优越性。这项工作为非π共轭基团的修饰提供了一种新范式，并将指导和加速短波长区域新型双折射晶体的探索。
