Kee Joonhyuk, Ok Kang Min
Department of Chemistry, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul, 04107, Korea.
Angew Chem Int Ed Engl. 2021 Sep 13;60(38):20656-20660. doi: 10.1002/anie.202106812. Epub 2021 Jul 5.
Four chiral coordination polymers (CPs), M[(S,S)-C H N O ] and M[(R,R)-C H N O ] (M=Zn or Cd), have been exclusively synthesized in high yields with the aid of newly designed chiral ligand under hydrothermal condition. The CPs crystallizing in the orthorhombic nonpolar space group, C222 , reveal three-dimensional framework structures composed of MO tetrahedra and the corresponding homochiral linkers. Powder second-harmonic generation (SHG) measurements indicate that the nonpolar CPs reveal very strong SHG efficiency of ca. 5-9 times that of KH PO and exhibit type-I phase-matching behavior. Density functional theory calculations suggest that the unusually large SHG efficiency found from the nonpolar CPs should be attributable to the synergistic effect of polarizable metal cations and enhanced hyperpolarizability in the donor-acceptor system originating from the hydrogen bonding in the coordinated linkers.
在水热条件下，借助新设计的手性配体，已独家高产合成了四种手性配位聚合物（CPs），即M[(S,S)-C₈H₁₄N₂O₂]和M[(R,R)-C₈H₁₄N₂O₂]（M = Zn或Cd）。这些CPs在正交非极性空间群C222中结晶，呈现出由MO₄四面体和相应的同手性连接体组成的三维框架结构。粉末二次谐波产生（SHG）测量表明，这些非极性CPs显示出非常强的SHG效率，约为KH₂PO₄的5 - 9倍，并表现出I型相位匹配行为。密度泛函理论计算表明，从非极性CPs中发现的异常大的SHG效率应归因于可极化金属阳离子的协同效应以及源自配位连接体中氢键的供体 - 受体系统中超极化率的增强。
