Institute for Materials Chemistry and Engineering, Kyushu University , 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
Department of Chemistry, Graduate School of Science, Kobe University , Kobe, Hyogo 657-8501, Japan.
J Am Chem Soc. 2016 Nov 2;138(43):14170-14173. doi: 10.1021/jacs.6b05089. Epub 2016 Oct 24.
The polarization switching mechanism is used in various devices such as pyroelectric sensors and memory devices. The change in polarization mostly occurs by ion displacement. The development of materials whose polarization switches via electron transfer in order to enhance operation speed is a challenge. We devised a synthetic and crystal engineering strategy that enables the selective synthesis of a [CrCo] heterometallic dinuclear complex with a polar crystal structure, wherein polarization changes stem from intramolecular charge transfer between Co and the ligand. Polarization can be modulated both by visible-light irradiation and temperature change. The introduction of chiral ligands was paramount to the successful polarization switching in the valence tautomeric compound. Mixing Cr and Co complexes with enantiopure chiral ligands resulted in the selective formation of only pseudosymmetric [CrCo] heterometallic complexes. Furthermore, the left-handed chiral ligands preferentially interacted with their right-handed counterparts, enabling molecules to form a polar crystal structure.
极化反转机制用于各种设备中，如热释电传感器和存储设备。极化的变化主要通过离子位移发生。开发通过电子转移进行极化反转以提高操作速度的材料是一项挑战。我们设计了一种合成和晶体工程策略，能够选择性合成具有极性晶体结构的[CrCo]杂金属双核配合物，其中极化变化源于 Co 和配体之间的分子内电荷转移。极化可以通过可见光照射和温度变化来调节。手性配体的引入对于价态互变异构化合物中极化反转的成功至关重要。将 Cr 和 Co 配合物与手性纯手性配体混合，只会选择性地形成假性对称的[CrCo]杂金属配合物。此外，左手性手性配体优先与右手性手性配体相互作用，使分子形成具有极性晶体结构的配合物。
