Chang Tian, Qu Di, Li Bao, Wu Lixin
State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China.
Molecules. 2022 Nov 2;27(21):7447. doi: 10.3390/molecules27217447.
Vanadomolybdates (VMos), comprised of Mo and V in high valences with O bridges, are one of the most important types of polyoxometalates (POMs), which have high activity due to their strong capabilities of gaining/losing electrons. Compared with other POMs, the preparation of VMos is difficult due to their relatively low structural stability, especially those with unclassical architectures. To overcome this shortcoming, in this study, triol ligands were applied to synthesize VMos through a beaker reaction in the presence of VO, NaMoO, and organic species in the aqueous solution. The single-crystal X-ray diffraction results indicate that two VMo clusters, Na{VMoO[CHC(CHO)]}∙13HO and Na{VMoO[CHCHC(CHO)]}∙13HO, with a similar architecture, were synthesized, which were both stabilized by triol ligand and {MoO} polyhedron. Both clusters are composed of five V ions and one Mo ion in a classical Lindqvist arrangement with an additional Mo ion, showing an unprecedented hepta-nuclear VMo structure. The counter Na cations assemble into one-dimensional channels, which facilitates the transport of protons and was further confirmed by proton conductivity experiments. The present results provide a new strategy to prepare and stabilize VMos, which is applicable for developing other compounds, especially those with untraditional architectures.
钒钼酸盐（VMos）由高价态的钼（Mo）和钒（V）通过氧桥连接而成，是多金属氧酸盐（POMs）中最重要的类型之一，因其具有很强的得失电子能力而具有高活性。与其他多金属氧酸盐相比，钒钼酸盐的制备较为困难，因为它们的结构稳定性相对较低，尤其是那些具有非经典结构的钒钼酸盐。为了克服这一缺点，在本研究中，三醇配体被用于在水溶液中VO、NaMoO和有机物种存在的情况下通过烧杯反应合成钒钼酸盐。单晶X射线衍射结果表明，合成了两个结构相似的钒钼簇，Na{VMoO[CHC(CHO)]}∙13HO和Na{VMoO[CHCHC(CHO)]}∙13HO，它们均由三醇配体和{MoO}多面体稳定。两个簇均由五个V离子和一个Mo离子以经典的Lindqvist排列方式以及一个额外的Mo离子组成，呈现出前所未有的七核钒钼结构。抗衡Na阳离子组装成一维通道，这有利于质子传输，质子传导率实验进一步证实了这一点。目前的结果为制备和稳定钒钼酸盐提供了一种新策略，该策略适用于开发其他化合物，尤其是那些具有非传统结构的化合物。
