{Nb₂₈₈O₇₆₈(OH)₄₈(CO₃)₁₂}: A Macromolecular Polyoxometalate with Close to 300 Niobium Atoms

Abstract

Aprotein-sized (ca. 4.2 4.2 3.6 nm 3 )non-biologically derived molecule {Nb 288 O 768 (OH) 48 (CO 3 ) 12 }( Nb 288 ) containing up to 288 niobium atoms has been obtained, which is by far the largest and the highest nuclearity polyoxoniobate (PONb). Particularly,i nt erms of metal nuclearity number, Nb 288 is the second largest cluster so far reported in classic polyoxometalate chemistry (V,M o, W, Nb, and Ta). Nb 288 can be described as agiant windmill-like cluster aggregate of six nanoscale high-nuclearity PONb units {Nb 47 O 128 (OH) 6 (CO 3 ) 2 }( Nb 47 )j oined together by six additional Nb ions.I nterestingly,t he 47-nuclearity Nb 47 units generated in situ can be isolated and bridged by copper complexes to form an inorganic-organic hybrid three-dimensional PONb framework, which exhibits effective catalytic activity for hydrolyzing nerve agent simulant of dimethyl methylphosphonate.T he unique Nb 47 cluster also provides anew type of topology to very limited family of Nb-O clusters.

Structural Characterization of a High‐Nuclearity Niobium(V) Carboxylate Cluster Based on Pivalic Acid

“…The most notable feature of the described complex is its nuclearity, which is highest to date for structurally characterized niobium carboxylates. Niobium has been shown to form remarkably high‐nuclearity polyoxoanions (known as polyoxoniobates) such as the recently reported species containing 114 [34] and 288 [35] niobium centers. In contrast to the purely inorganic polyoxoniobates, carboxylate‐terminate clusters display much smaller nuclearity; prior to this report the largest nuclearity was a dodecanuclear carboxylate cluster [33] …”

Polyoxometalates: Tailoring metal oxides in molecular dimension toward energy applications

“…312 Cobalt-containing and chromium-containing polyoxoniobates such as Na 6 12 has been successfully produced. 336 Their electronic and optical properties deserve more careful scrutiny for energy applications.…”

“…Cobalt‐containing and chromium‐containing polyoxoniobates such as Na 6 K 12 [H 2 Co 8 O 4 (Nb 6 O 19 ) 4 ]·39H 2 O are produced to demonstrate their novel electronic and magnetic properties . Novel polyoxoniobate structures have been constructed; for example, polyoxoniobates with a large number of niobium atoms based on Nb 114 , Nb 81 , Nb 52 , Cu 3 Nb 78 , and Cu 4 Nb 78 have been synthesized, while an even larger‐size polyoxoniobate Nb 288 O 768 (OH) 48 (CO 3 ) 12 has been successfully produced . Their electronic and optical properties deserve more careful scrutiny for energy applications.…”

Research advances of polyoxotantalates

“…而有关多钽 氧酸簇聚物的报道极少, 目前同多钽酸簇聚物的聚 集度也仅仅是十核之低 [17] . 需要指出的是 [12] , Nb 288 [13] , Mo 368 [14] , W 200 [15] . [29] 在1976年获…”