Rational addition of capping groups to the phosphomolybdate Keggin anion [PMo12O40]3− by mild, non-aqueous reductive aggregation

Abstract

Controlled reductive assembly of capped Keggin anions [PMo(12)O(40)(ML(m))(n)](3-) has been achieved by reduction of [PMo(12)O(40)](3-) with sodium-mercury amalgam in the presence of metal halides, as exemplified by the rational syntheses of mono-capped [PMo(12)O(40){Co(MeCN)(2)}](3-) and bi-capped [PMo(12)O(40)(VO)(2)](3-) and [PMo(12)O(40)Sb(2)](3-).

A covalent polyoxomolybdate-based hybrid with remarkable electron reservoir properties

“…Due to more accessible reduction processes (potentials are generally shifted by +0.5 V compared to the tungstate analogues), 22 the molybdenum analogues are best suited for applications based on electronic properties. [23][24][25] However they are more labile and their vacant derivatives are less stable than their tungstate analogues, particularly in aqueous solutions. As a consequence, their derivatisation has been scarcely developed, [26][27][28][29] and to the best of our knowledge, no post-functionalisable hybrids of these electronically attractive polyoxomolybdates have been reported.…”

Coordination capacity of Keggin anions as polytopic ligands: case study of [VNb12O40]15−

“…14 One of the possibilities to increase the basicity of Keggin type POMs without lacunarization is multielectron reduction with the retention of the Keggin structure, e.g., reduction of [PMo12O40] 3to [PMo12O40] 5or to even more negative species, that increases the ability of coordinating various heterometals. 15,16 Another possibility, which still needs to be explored, is to use Keggin anions with X 2+ hetroatoms, such as [BeW12O40] 6-. 17 However, sometimes this synthetic approach is thwarted due to the competition between the central heteroatom and the heterometal addenda in the metalate backbone, and may produce unexpected results.…”

A redox-triggered structural rearrangement in an iodate-templated polyoxotungstate cluster cage

“…Notably, this is also the first example of a Dawson-like {W 18 } cluster cage containing pyramidal XO 3 templates to adopt an 'olive' shape with a {XW 18 } composition. 17 In summary, we have discovered a new type of tungstatoiodate, [H 5 W 18 O 59 (IO 3 )] 6À , which contains iodine(V) within a {W 18 O 54 } Dawson-type shell and is the first example of an a-isomer of this family. We have characterized this polyanion using single crystal structure analysis and confirmed the assignment of the central atom of the template anion as iodine, as well as the degree of cluster protonation using mass spectrometry.…”