An Exceptional Thermally Induced Four‐State Nonlinear Optical Switch Arising from Stepwise Molecular Dynamic Changes in a New Hybrid Salt. Issue 2 (25th November 2021)

• Record Type: Journal Article
• Authors: Zeng, Ying; Hu, Chun‐Li; Xu, Wei‐Jian; Zeng, Teng‐Wu; Zhu, Zhao‐Xiang; Chen, Xiao‐Xian; Liu, De‐Xuan; Chen, Yu‐Jie; Zhang, Yue‐Biao; Zhang, Wei‐Xiong; Chen, Xiao‐Ming
• Is Part Of: Angewandte Chemie international edition. Volume 61:Issue 2(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-11-25
• Subjects: hybrid salt -- molecular dynamics -- multistep reversible phase transitions -- nonlinear optical switches; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202110082
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Switching materials in channels of nonlinear optics (NLOs) are of particular interest in NLO material science. Numerous crystalline NLO switches based on structural phase transition have emerged, but most of them reveal a single‐step switch between two different second‐harmonic‐generation (SHG) states, and only very rare cases involve three or more SHG states. Herein, we report a new organic‐inorganic hybrid salt, (Me3 NNH2 )2 [CdI4 ], which is an unprecedented case of a reversible three‐step NLO switch between SHG‐silent, ‐medium, ‐low, and ‐high states, with high contrasts of 25.5/4.3/9.2 in a temperature range of 213–303 K. By using the combined techniques of variable‐temperature X‐ray single‐crystal structural analyses, dielectric constants, solid‐state 13 C nuclear magnetic resonance spectroscopy, and Hirshfeld surface analyses, we disclose that this four‐state switchable SHG behavior is highly associated with the stepwise‐changed molecular dynamics of the polar organic cations. This finding demonstrates well the complexity of molecular dynamics in simple hybrid salts and their potential in designing new advanced multistep switching materials. Abstract : A new simple hybrid salt has been synthesized that exhibits reversible multistep phase transitions and an unprecedented thermally induced three‐step "silent‐medium‐low‐high" second‐harmonic‐generation switching behavior. This behavior arises from complex and stepwise molecular dynamic changes of the polar organic cations.