Qi Lu, Jiang Xingxing, Duanmu Kaining, Wu Chao, Lin Zheshuai, Huang Zhipeng, Humphrey Mark G, Zhang Chi
China-Australia Joint Research Center for Functional Molecular Materials, School of Chemical Science and Engineering, Tongji University, Shanghai 200092, China.
Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
J Am Chem Soc. 2024 Apr 10;146(14):9975-9983. doi: 10.1021/jacs.4c00666. Epub 2024 Mar 11.
Oxides have attracted considerable attention owing to their potential for nonlinear optical (NLO) applications. Although significant progress has been achieved in optimizing the structural characteristics of primitives (corresponding to the simplest constituent groups, namely, cations/anions/neutral molecules) comprising the crystalline oxides, the role of the primitives' interaction in determining the resultant functional structure and optical properties has long been underappreciated and remains unclear. In this study, we employ a π-conjugated organic primitive confinement strategy to manipulate the interactions between primitives in antimonates and thereby significantly enhance the optical nonlinearity. Chemical bonds and relatively weak H-bonding interactions promote the formation of and Sb(III)-based dimer configurations in (CHNO)(SbOF) (4-HPYSOF) and (CHN)(SbF) (4-APSF), respectively, resulting in very different second-harmonic generation (SHG) efficiencies and birefringences. In particular, 4-HPYSOF displays an exceptionally strong SHG response (12 × KHPO at 1064 nm) and a large birefringence (0.513 at 546 nm) for a Sb(III)-based NLO oxide as well as a UV cutoff edge. Structural analyses and theoretical studies indicate that polarized ionic bond interactions facilitate the favorable arrangement of both the inorganic and organic primitives, thereby significantly enhancing the optical nonlinearity in 4-HPYSOF. Our findings shed new light on the intricate correlations between the interactions of primitives, inorganic primitive configuration, and SHG properties, and, more broadly, our approach provides a new perspective in the development of advanced NLO materials through the interatomic bond engineering of oxides.
由于其在非线性光学（NLO）应用方面的潜力，氧化物已引起了广泛关注。尽管在优化构成晶体氧化物的基元（对应于最简单的组成基团，即阳离子/阴离子/中性分子）的结构特征方面已取得了显著进展，但基元间相互作用在决定最终功能结构和光学性质方面所起的作用长期以来一直未得到充分重视且仍不清楚。在本研究中，我们采用π共轭有机基元限制策略来调控锑酸盐中基元之间的相互作用，从而显著增强光学非线性。化学键和相对较弱的氢键相互作用分别促进了(CHNO)(SbOF)（4-HPYSOF）和(CHN)(SbF)（4-APSF）中基于Sb(III)的二聚体构型的形成，导致二次谐波产生（SHG）效率和双折射有很大差异。特别是，对于基于Sb(III)的NLO氧化物以及紫外截止边缘，4-HPYSOF显示出异常强的SHG响应（在1064 nm处为12×KHPO）和大的双折射（在546 nm处为0.513）。结构分析和理论研究表明，极化的离子键相互作用有利于无机和有机基元的良好排列，从而显著增强了4-HPYSOF中的光学非线性。我们的研究结果为基元相互作用、无机基元构型和SHG性质之间的复杂关联提供了新的见解，更广泛地说，我们的方法通过氧化物的原子间键工程为先进NLO材料的开发提供了新的视角。
