A {Co₄O₄} Cubane Incorporated within a Polyoxoniobate Cluster

Abstract

A novel octacobalt-containing polyoxoniobate, Na6 K12 [H2 Co8 O4 (Nb6 O19 )4 ]⋅39 H2 O, has been prepared by a combination of hydrothermal and diffusion methods. The polyanion [H2 Co8 O4 (Nb6 O19 )4 ](18-) incorporates a tetrameric assembly of Lindqvist-type [Nb6 O19 ](8-) fragments trapping a {Co(II) 4 Co(III) 4 } cluster which comprises a central {Co(III) 4 O4 } cubane core, surrounded by another four Co(II) ions linkers. Furthermore, magnetic measurements show that the compound exhibits antiferromagnetic interactions.

An {As4Cu4[Cu(H2O)]12} Cluster Incorporated within Four [Nb7O22]9− Units

“…In 2015, a octavanadium‐substituted PONb [Nb 48 V 8 (OH) 30 O 130 ] 18− was found by Su et al . In recent years, our group reported a series of TM‐substituted PONbs [Co 14 (OH) 16 (H 2 O) 8 Nb 36 O 106 ] 20− , [H 2 Co 8 (Nb 6 O 19 ) 4 ] 18− , [Cu 24 (Nb 7 O 22 ) 8 H 23 NaO 8 ] 16− , [H 9 Cu 25.5 O 8 (Nb 7 O 22 ) 8 ] 28− ,and [H 4 Ni 10 (H 2 O) 8 Nb 32 O 102 ] 20− , which are constructed by [Nb 6 O 19 ] 8− or [Nb 7 O 22 ] 9− units and TM clusters.…”

Polyoxometalates: Tailoring metal oxides in molecular dimension toward energy applications

“…Polyoxoniobate‐based composites such as those coupled with polyoxovanadate are used as efficient catalysts . 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 .…”

Synthesis, structure, and photocatalytic hydrogen evolution of a trimeric Nb/W addendum cluster

“…[3][4][5][6] This family has accelerated dramatically over the last 15 years, and a vast expansion of available PONbs has been reported. [7][8][9][10][11][12][13][14] In this context, the class of Nb/W addendum heteropolyoxometalates develops slowly since the pioneering work reported by Finke and Droege in 1984. 15 Recently, some other Nb/W addendum heteropolyoxometalate clusters have been communicated.…”