Polyoxometallate aus Gold – das Polyoxoaurat [Au^III₄As^V₄O₂₀]⁸⁻

Synthesis and Characterization of the Dicopper(II)‐Containing 22‐Palladate(II)[CuII2PdII22PV12O60(OH)8]20−

“…In 6 ] 8À ("Pd 13 As 8 ") was reported, which consists of a cuboctahedral {Pd 12 } cage, a central Pd II guest, and eight {AsO 4 } capping groups leading to an overall cubic shape of the polyanion. [1a] Later it was shown that the {As 9À , which is the selenite analogue of "Pd 15 P 10 ".…”

“…

The recently discovered area of water-soluble noble-metalbased polyoxometalates (POMs) [1a] is currently developing fast, not only because of their interesting structures and properties but also because of the promising applications of these compounds. [1][2][3][4][5] Currently polyoxopalladates(II) are the noble-metalbased polyanion family comprising the largest number of members.In 2008 the parent 13-palladate [Pd II 13 As V 8 O 34 (OH) 6 ] 8À ("Pd 13 As 8 ") was reported, which consists of a cuboctahedral {Pd 12 } cage, a central Pd II guest, and eight {AsO 4 } capping groups leading to an overall cubic shape of the polyanion. [1a] Later it was shown that the {As V O 4 } 3À capping groups can also be replaced by {Se IV O 3 } 2À or {PhAs V O 3 } 2À , which unexpectedly lead to coordination numbers of 6 (octahedral) and even 8 (cubic), respectively, for the central Pd II .

…”

Oxo‐Metalate Building Blocks: Conceptual Competitors for Tetravalent Carbon?

“…This inaugurated new directions in synthesis, leading to an explosion in reports of a variety of compounds for use in an expanding range of applications. This tendency was supported by the fact that POM reduction potentials, acidities, and other properties are relevant, for example, for green chemistry, [8] renewable energy (Figure 3), [9][10][11] or catalysis [12,13] (model compounds are also considered [14] ). Parallel to the above developments, the discovery of giant molybdenum/tungsten oxide clusters (obtained under reducing conditions according to a type of growth process) containing up to 368 metal atoms [15] was considered by the scientific community as a breakthrough because it was the route to new length scales and provided the option to discover a variety of new phenomena, including those related to processes under confined conditions.…”

The Mixed Gold–Palladium Polyoxo‐Noble‐Metalate [NaAuIII4PdII8O8(AsO4)8]11−

“…[8] To date more than 40 polyoxopalladates(II) of different shape, size, and composition have been prepared following this simple synthetic strategy, by using various external heterogroups RXO 3 nÀ (X = P V , As V , Se IV , V V ; and R= O, Ph, lone pair) and many different central metal ion guests. [9][10][11] A similar approach was also successfully applied for the condensation of [Au(OH) 4 [12] Interestingly, for the arsenate derivative Au 4 As 4 two polyanions are linked in the solid state via a belt of five Na + countercations into a cuboid-shaped assembly Na 5 -(Au 4 As 4 ) 2 , [12a] with a structure resembling the polyoxopalladate family [MPd II 12 O 8 (RXO 3 ) 8 ] nÀ (MPd 12 X 8 ). [11] This inspired us to try and replace the four peripheral Na + ions in such Na 5 (Au 4 As 4 ) 2 assembly by Pd II ions.…”

“…All noble metal centers in Au 4 Pd 8 have a square-planar coordination geometry with MÀO bond lengths in the range of 1.980 (5)-2.028(13) , which is expected. [7][8][9][10][11][12][13] The As V ÀO bond lengths within the tetrahedral AsO 4 groups are 1.690 (13) for the three m 2 -O atoms bridging the As V and Au III /Pd II centers, and 1.70 (3) for the terminal oxo-ligand.…”