多酸亚胺化与手性多酸分子的构筑(2)

这项工作进一步开拓了以可控方式合成手性多酸化合物的途径, 不仅解决了在多酸簇上进行大环修饰的难题,

而且实现了合成多酸金属大环化合物

沿着特定方向堆积形成1D纳米隧道

图9 化合物8的阴离子通过氢键连接成为2D波形网状结构,

的历史性突破.

4 结论与展望

基于分子设计和分子工程学的原理, 利用DCC 脱水法, 通过多酸的可控组装, 设计合成了多种多酸基有机-无机杂化分子, 特别是手性多酸分子. 虽然取得了一定的成果, 但手性多酸分子的构筑研究依然是一个难度大的挑战课题. 这是因为手性化合物大多是以对映异构体外消旋的形式存在, 它们表现出相同的化学性质并且在物理性质上大多相同, 拆分它们极其困难, 而且多数具有手性结构的多酸化合物在溶液中不稳定, 容易迅速消旋而失去旋光活性, 所以真正得到的纯手性多酸化合物并不多, 对多酸手性化合物的研究目前仍处于起步阶段, 还存在许多问题需要探索. 随着多酸化学研究的不断深入, 相信在不久的将来, 一定会有大量的手性多酸分子

图8 化合物7和9的阴离子通过C–H···O连接成为一维

无限延伸的链

被合成出来.不仅如此, 手性多酸有机-无机杂化分子材料以其独特的结构和性质, 在光电转换、催化、药物及影像物理等领域具有巨大的应用价值.

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Imidoylation of polyoxometalates and fabrication of chiral polyoxometalates

WU PingFan1,2, ZHANG Jin2, XU Xiao1, XIAO FengPing2, HAO Jian2 & WEI YongGe2

12

School of Chemical & Environmental Engineering, Hubei University of Technology, Wuhan 430068, China; Department of Chemistry, Tsinghua University, Beijing 100084, China

The synthesis of chiral polyoxometalates (POMs) has attracted increasing attention in recent years. The aim of this research was to construct different rigid POMs with organic derivatives. The POMs were synthesized with C–C or C–N links using N,N'-dicyclo- hexylcarbodiimide (DCC) protocol. The synthesized POMs are probably chiral because of increased steric hindrance of the bulky POMs to rotation at the C–N or C–C bond. Novel diorganoimido-substituted POM-based chiral macrocycles were synthesized using the DCC protocol. The POM macrocycles were produced in a controllable manner from achiral Lindqvist hexamolybdate and bis aryl amines bearing o-alkoxy chain substituents. Recent advances in synthesis of chiral POMs based on organoimido-substituted POMs are reviewed.

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