Liu Bin-Wen, Jiang Xiao-Ming, Zeng Hui-Yi, Guo Guo-Cong
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, P. R. China.
J Am Chem Soc. 2020 Jun 17;142(24):10641-10645. doi: 10.1021/jacs.0c04738. Epub 2020 Jun 4.
Noncentrosymmetry (NCS) is a prerequisite for second-order nonlinear optical (NLO) materials. In this work, a new polycation-substitution-induced centrosymmetry (CS)-to-NCS transformation strategy was applied in CS RbGaS, affording two novel NCS salt-inclusion chalcogenides: [ABaCl][GaS] (A = Rb, ; Cs, ). Remarkably, they exhibit the key merits of both Vis and IR NLO candidates, including strong phase-matchable second harmonic generation intensities (10.4-15.3 × KHPO at 1064 nm; 0.9-1.0 × AgGaS at 1910 nm), high laser-induced damage thresholds (11-12 × AgGaS), and a wide transparent window. Their prominent NLO performances originate from the orderly packing of T2-supertetrahedral GaS motifs resulting from the template effect of acentric polycation [ClABa]. The CS-to-NCS transformation first realized by polycation-substitution-induced NLO-functional motif ordering provides an effective approach for designing new NLO materials.
非中心对称性（NCS）是二阶非线性光学（NLO）材料的一个先决条件。在这项工作中，一种新的多阳离子取代诱导的中心对称性（CS）到NCS转变策略被应用于CS型RbGaS中，得到了两种新型的NCS盐包合硫族化物：[ABaCl][GaS]（A = Rb， ；Cs， ）。值得注意的是，它们展现出了可见光和红外NLO候选材料的关键优点，包括强的可相位匹配的二次谐波产生强度（在1064 nm处为10.4 - 15.3×KHPO ；在1910 nm处为0.9 - 1.0×AgGaS ）、高的激光诱导损伤阈值（11 - 12×AgGaS ）以及宽的透明窗口。它们卓越的NLO性能源于由非中心多阳离子[ClABa]的模板效应导致的T2 - 超四面体GaS基序的有序堆积。通过多阳离子取代诱导NLO功能基序有序排列首次实现的CS到NCS转变为设计新型NLO材料提供了一种有效方法。
