Vanadium oxide clusters as building blocks for the synthesis of metal oxide surfaces and framework materials:: Synthesis and x-ray crystal structure of [H6Mn3VIV15VV4O46(H2O)12].30H2O

While a large number of important industrial chemical transformations take place on the catalytic transition metal oxide surfaces, the mechanism of their interaction with substrate molecules is less understood due mainly to the complex nature of these poorly characterized surfaces that are inaccessible to many physicochemical techniques.(1) The suitability of currently em employed catalytic surfaces is determined empirically with practically little or no possibility of improvements in their performance. The idea of rational synthesis of well characterizable metal oxide surfaces with desired features to meet the environmental and technological challenges of modern times(1a,g,2) is, therefore, considerably appealing.(1e,g,3) Transition metal oxide clusters or polyoxometalates and their derivatives, which are perceived to represent structure and bonding in infinite metal oxide surfaces,(1d,4) provide remarkably diverse and well-defined building blocks suitable for generating nanosized molecular systems.(4a,5) However, assembling of the well-characterizable metal oxide clusters, without using conventional organic ligands, to prepare desired 3-D framework materials and true solid surfaces composed purely of well-defined transition metal oxide building blocks remains a rewarding challenge. By adopting a simple synthetic approach we have now been able to prepare novel framework materials based 100% on well-defined metal oxide building blocks without incorporating any conventional organic or inorganic (e.g. PO43-, ASO(4)(3-), SO42-, etc.) ligands. This report describes the synthesis and characterization of the new solid-[(H6Mn3V15V4O46)-V-IV-O-V(H2O)(12)]. 30H(2)O (1) by complete single-crystal X-ray structure analysis, elemental analysis, manganometric titration, TGA, and FT-IR spectroscopy.