A Molecular Placeholder Strategy To Access a Family of Transition-Metal-Functionalized Vanadium Oxide Clusters

作者：Kastner Katharina; Margraf Johannes T; Clark Timothy; Streb Carsten^*

来源：Chemistry - A European Journal, 2014, 20(38): 12269-12273.

DOI：10.1002/chem.201403592

• functionalization
• metal oxide clusters
• polyoxometalates
• polyoxovanadates
• self-assembly

Systematic access to metal-functionalized polyoxometalates has thus far been limited to lacunary tungsten oxide and molybdenum oxide clusters. The first controlled, stepwise bottom-up assembly route to metal-functionalized molecular vanadium oxides is now presented. A di-vacant vanadate cluster with two metal binding sites, (DMA)(2)[V12O32Cl](3-) (DMA= dimethylammonium) is formed spontaneously in solution and characterized by single-crystal X-ray diffraction, ESI mass spectrometry, V-51 NMR spectroscopy, and elemental analyses. In the cluster, the metal binding sites are selectively blocked by hydrogen-bonded DMA placeholder cations. Reaction of the cluster with transition metals TM (Fe3+, Co2+, Cu2+, Zn2+) gives access to mono-functionalized vanadate clusters (DMA)[{TM(L)}V12O32Cl](n-) (L= ligand). Metal binding is accomplished by significant distortions of the vanadium oxide framework reminiscent of a pincer movement. Cluster stability under technologically relevant conditions in the solid-state and solution is demonstrated.

• 出版日期2014-9-15