Structure and dynamics of a chiral cubanoid complex composed of lithium and salphen
Structure and dynamics of a chiral cubanoid complex composed of lithium and salphen
复制标题
锂和 Salphen 组成的手性立方体配合物的结构和动力学
DOI：
10.1016/j.ica.2020.119894
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发表时间：
2020
影响因子：
2.8
通讯作者：
Tanaka Kentaro
中科院分区：
文献类型：
--
作者：
Kawano Shin-ichiro;Tomita Kyohei;Tanaka Kentaro
锂离子由于其广泛的应用而受到越来越多的关注，例如在轻质能源器件和功能晶体中。为了了解锂离子在材料科学和基础化学中的科学作用，阐明锂配合物的配位结构和动力学性质是很重要的。然而，在众多的配位结构文库中，对含有锂和salphen的配位配合物（N,N ' -o-phenylenebis(salicylideneimine),Salp）的研究很少。本文描述了一种由锂离子和salpligands组成的立方体配合物的分子结构，并详细研究了这些对映体配合物之间的平衡。x射线晶体学分析表明，该配合物具有一个由两个salpligands手性取向包围的立方体结构。刚性salpligand倾向于五坐标锂中心的方形金字塔结构。通过变温核磁共振（VT）、扩散有序核磁共振（1H-DOSY）和电喷雾电离飞行时间质谱（ESI-TOF MS）分析，详细表征了两种对映体在有机溶剂中的平衡。结果表明，在低温条件下，对映体立方烷结构之间的交换速率与溶剂有关，且交换速率较低。
Lithium ions have gained increasing attention due to their wide range of applications, e.g., in lightweight energy devices and functional crystals. In order to understand the scientific role of the lithium ion in materials science as well as fundamental chemistry, it is important to elucidate the coordination structures and dynamic properties of lithium complexes. However, in the numerous libraries of coordination structures, the coordination complexes containing lithium and salphen (N,N’-o-phenylenebis(salicylideneimine),Salp) have been scarcely studied. Herein, we describe a molecular structure of a cubanoid complex composed of lithium ions andSalpligands, and the detailed investigation of the equilibrium between the enantiomeric complexes. X-ray crystallographic analysis revealed that the complex has a cubane structure surrounded by twoSalpligands in a chiral orientation. The rigidSalpligand favors a square-pyramidal structure of the five-coordinate lithium center. The equilibrium between the two enantiomers in organic solvents is characterized in detail by variable-temperature (VT)-NMR, diffusion-ordered (1H-DOSY) NMR, and electrospray ionization time-of-flight mass spectroscopy (ESI-TOF MS) analyses. The results indicated that the exchange rate for the structural conversion between the enantiomeric cubane structures is solvent-dependent and low at low temperature.