Synthesis and Electrochemistry of the Monolacunary Dawson‐Type Tungstoarsenate [H₄AsW₁₇O₆₁]¹¹⁻ and Some First‐Row Transition‐Metal Ion Derivatives

Abstract

The novel family of the Dawson-type tungstomonoarsenate [H 4 AsW 18 O 62 ] 7− has been extended by preparing for the first time its monolacunary species and its first-row transitionmetal ion substituted derivatives. All compounds were characterized by elemental analysis, IR and UV/Vis spectroscopy and representative examples by 183 W NMR spectroscopy. Several lines of experimental evidence converge to indicate that the substitution occurs in the α 2 position. The lacunary species, unlike its phosphorus analogue, was sufficiently stable for a few voltammetric runs. Therefore, the cyclic vol-

Polyoxometalate clusters, nanostructures and materials: From self assembly to designer materials and devices

“…In recent years, POM chemists have noted that one of the two hetero atoms in the conventional Dawson clusters could be ''removed'' to form semivacant clusters; this was observed in the monolacunary Dawson-type tungstoarsenate [H 4 AsW 17 O 61 ] 112 and its first-row transition-metal ion derivatives. 55 X-Ray determination confirmed the configuration of a semivacant Dawson polyoxotungstate skeleton in the structures of [Ce{X(H 4 )W 17 O 61 } 2 ] (X = P, As) and even indicate the probable location of internal protons. Bond valence sum calculations for these structures show that the four protons required for charge balance in all salts of the {XW 18 } anions and their lacunary derivatives are almost certainly bound to the oxygen atoms of the empty tetrahedra.…”

Cyclic Voltammetry Study of the Mn‐Substituted Polyoxoanions [MnII4(H2O)2(H4AsW15O56)2]18− and [((MnIIOH2)MnII2PW9O34)2(PW6O26)]17−: Electrodeposition of Manganese Oxides Electrocatalysts for Dioxygen Reduction

“…In media of pH 5, comparison between the cyclic voltammetry curves of Mn 4 [16,35]. This demonstrates that the replacement of two As V heteroatoms in the symmetrical Dawson-type Mn 4 As 4 W 30 by two hydrogen atoms in the dissymmetrical Dawson-complex Mn 4 As 2 W 30 has no significant influence on the electron transfer within the molecule.…”

Novel Tungstovanadate Wells−Dawson Organic–Inorganic Heteropolyoxometalate Compound: Synthesis and Crystal Structure of [Cu2(2,2′-bipy)2(Inic)2(H2O)2][Y(Inic)2(H2O)5]H3[V2W18O62]·5.5H2O (Where 2,2′-bipy = 2,2′-Bipyridine, Inic = γ-Picolinic Acid)

“…Polyoxometalates (POMs), one type of well-known polynuclear metal−oxo cluster with an unmatched structure variety, have attracted great attention to materials chemistry owing to their potential applications in catalysis, medicine, and material science. – Studies on the syntheses of inorganic/organic hybrid materials built by POM building blocks and metal coordination compounds have been developed well recently. – In recent years, two types of POMs which are widely explored have been the famous Keggin and Wells−Dawson families, – which can be represented by [XM 12 O 40 ] n − and [X 2 M 18 O 62 ] n − (X = P V , Si IV ; M = W V,VI , Mo V,VI , V IV,V ), respectively. As far as we know, among the reports of the Wells−Dawson POMs, the crystal structure of vanadium atoms as heteroatoms has never been reported.…”

“…In summary, a novel tungstovanadate Wells−Dawson organic–inorganic heteropolyoxometalate compound has been hydrothermally synthesized. Although a vast amount of Wells−Dawson POMs have been reported in recent years, – ,– few of their heteroatoms have been transition metals so far. The successful isolation of 1 shows the perspective of extending the POM family through reasonable selection of the POM clusters, transition metals, and organic ligands.…”

“…[1][2][3][4] Studies on the syntheses of inorganic/organic hybrid materials built by POM building blocks and metal coordination compounds have been developed well recently. [5][6][7] In recent years, two types of POMs which are widely explored have been the famous Keggin and Wells-Dawson families, [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] which can be represented by [XM 12 O 40 ] nand [X 2 M 18 O 62 ] n-(X ) P V , Si IV ; M ) W V,VI , Mo V,VI , V IV,V ), respectively. As far as we know, among the reports of the Wells-Dawson POMs, the crystal structure of vanadium atoms as heteroatoms has never been reported.…”