Wells-Dawson anion

Electrochemistry of a New family of Wells-Dawson Anions SemivacantTungstophosphates and Arsenates [H4XWi8062] (X = P... 

The anion [Ce4(0H)2(H20)9(P2Wi6059)2]14 (Figure 24) is isolated in good yield from reaction of Ce(NC>3)3 with Ki2H2P2Wi2048-nH20/ a hexavacant derivative of the Wells-Dawson anion U WisCfe]6-, and Na2W04. The anion has... 

Two isomers [al-P2Wi706i] ° and [a2-P2Wi706i] ° can be derived from the parent Wells-Dawson anion [a-P2Wi8062] by removal of a belt or cap W = Od unit, respectively. Complexes of RE ions with a lacunary [a-P2Wi706i] ° anion were first reported by Peacock and Weakley in 1971, which is now known as [RE(a2-P2Wi706i)2]" - The complex of the al isomer, [RE(al-P2Wi706i)]" , has also been prepared, although it could not be isolated. Until... 

Keggin anion [SiWn039] by a monovacant Wells-Dawson anion [a2-P2Wi706i] , has also been reported [48]. 

S.2.2.9 Monovacant Wells-Dawson Anions [a2-P2Wi706i] as Building Units... 

Figure 5.24 The two-dimensional layer structure of [Ln2(H20)9(a2-P2 Vi706i)]" [36]. (Reprinted with permission fromY. Lu, etal., New polyoxometalate compounds built up of lacunary Wells-Dawson anions and trivalent lanthanide cations, Inorganic Chemistry, 45, no. 5, 2055-2060 (Figure 3), 2006. 2006 American Chemical Society.)...

The [P8W480i84] anion shows a cyclic cluster structure constructed by four P2W12O48 units derived from a Wells-Dawson anion by removal of six adjacent W06 octahedra. In the complex RE4(H20)28[KcP8W480i84(H4W40i2)2RE2(H20)io] (RE = La, Ce, Pr,... 

Figure 1. Idealized Keggin, left, and Wells-Dawson anions, right.

The commonest lacunary polytungstates are derived from three plenary tungstate structures the C Lindqvist ) hexatungstate, [WgOig] the Keggin anion, typically a-[PWi204o] and the Wells-Dawson anion, typically a-[P2Wis062] -. 

The relevant lacunary versions of the Wells-Dawson anions are the two monovacant (oi and 02) and trivacant species shown in Figure 6. 

Figure 6. Three lacunary deivatives of the Wells-Dawson anion a-[P2Wi80g2] (a) ap [P2Wi70gi] ° (b) a2-[P2Wi70gi] ° (c) a-[P2Wi505g] ...

Lacunary Forms of Keggin and Wells-Dawson Anions 649... 

Figure 8 Numbering scheme for the a isomers of the Keggin and Wells-Dawson anions. The numbering is retained for the /3-isomer of the Keggin anion with the rotated triad containing atoms 10, 11, and 12.

Figure 9 Four Isomers of the Wells-Dawson anion (reprinted with permission of Elsevier from Contant, R. Thouvenot, R., Inorg. Chim. Acta 1993, 272, 41-50).

Electrochemistry of a New Family of Wells-Dawson Anions Semivacant Tungstophosphates and Arsenates [H4XWi8O6zf- (X=PorAs)... 

A. Ostuni, Lanthanide and actinide complexes of the lacunary Wells-Dawson anions synthesis, structure... 

I-P2W17O61] " and [a-2-P2Wi706i], isomers of the monovacant Wells-Dawson anion, and [a-B-PW9034] as building blocks to new lanthanide polyoxometalate materials. 

We are studying the solution and solid state properties of lanthanide complexes of the monovacant Wells-Dawson anions. A firm understanding of the solution and solid state chemistry is a prerequisite for the use of these units as building blocks in the preparation of new molecular based materials. 

When sodium tungstate is boiled with an excess of phosphoric acid the main heteropolytungstate products are two isomers of the Wells-Dawson anions and a smaller amount of another species (47). Crystallographic analysis of this species showed the composition of this anion to be [NaP5W3oOiio] ( P5W30, (47)) with the structure shown in Figure 39. ... 

Lopez X, Bo C, Poblet IM (2002) Electronic properties of polyoxometalates electron and proton affinity of mixed-Addenda Keggin and Wells-Dawson anions. J Am Chem Soc 124 12574-12582... 

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