Organic/Inorganic Species Synergistically Supported Unprecedented Vanadomolybdates

Abstract

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 V2O5, Na2MoO4, and organic species in the aqueous solution. The single-crystal X-ray diffraction results indicate that two VMo clusters, Na4{V5Mo2O19[CH3C(CH2O)3]}∙13H2O and Na4{V5Mo2O19[CH3CH2C(CH2O)3]}∙13H2O, with a similar architecture, were synthesized, which were both stabilized by triol ligand and {MoO6} 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.

Polyoxometalate-based frameworks for photocatalysis and photothermal catalysis

“…45 All the archetypal Anderson, Lindqvist, and Dawson clusters can be functionalized with tris. 15,[46][47][48][49][50] Recently, O. M. Yaghi's group reported a 3D PCOF with a 3-fold interpenetrated diamond topology via the imine condensation of an (amino-tris)-functionalized [MnMo 6 ]-POM linker and 4-connected tetrakis(4-formylphenyl)methane. 51 When the counter cation TBA + was exchanged as Li + , this hybrid framework became a prime candidate for solid-state electrolytes with high ionic conductivity, high Li + transference number, and good interfacial properties.…”

Organic-Cation Modulated Assembly Behaviors of a Ureidopyrimidone-Grafting Cluster

“…The bridging O atoms of some kinds of POMs can be replaced by organic molecules to obtain covalently modified organic-inorganic hybrids [24]. Among them, the method of replacing the coordinating O atoms around the central heteroatom of Anderson-Evans type POMs with triol ligands can introduce organic components with various structures and functional properties into POMs in the form of one-or two-side modification, thereby achieving synergistic functionalization of organic and inorganic components [25][26][27]. For example, by modifying two adeninyl groups on both sides of Anderson-Evans type POM and utilizing the double hydrogen bonds between two adeninyl groups, the main-chain type POM supramolecular polymer can be constructed, and exhibits thermally induced hybrid gel behaviors [28].…”

Special Issue: Research on Polyoxometalate Materials

“…Bao Li et al [ 7 ] synthesized two new compounds of vanadomolybdates with similar unprecedented hepta-nuclear structures, which were both stabilized by triol ligands. It is known that the preparation of vanadomolybdates is relatively difficult due to their low structural stability.…”