Dawson Type Heteropolyanions. 3.<sup>†</sup> Syntheses and <sup>31</sup>P, <sup>51</sup>V, and <sup>183</sup>W
NMR Structural Investigation of
Octadeca(molybdo−tungsto−vanado)diphosphates Related to the
[H<sub>2</sub>P<sub>2</sub>W<sub>12</sub>O<sub>48</sub>]<sup>12-</sup> Anion
Roland Contant
Mostefa Abbessi
René Thouvenot
Gilbert Hervé
10.1021/ic049885w.s001
https://acs.figshare.com/articles/journal_contribution/Dawson_Type_Heteropolyanions_3_sup_sup_Syntheses_and_sup_31_sup_P_sup_51_sup_V_and_sup_183_sup_W_NMR_Structural_Investigation_of_Octadeca_molybdo_tungsto_vanado_diphosphates_Related_to_the_H_sub_2_sub_P_sub_2_sub_W_sub_12_sub_O_sub_48_sub_sup_12_sup_Anion/3335812
The synthesis and multinuclear NMR characterization of mixed molybdenum−vanadium−tungsten polyoxometalates
[P<sub>2</sub>Mo<i><sub>x</sub></i>V<i><sub>y</sub></i>W<sub>18</sub><sub>-</sub><sub>(</sub><i><sub>x</sub></i><sub>+</sub><i><sub>y</sub></i><sub>)</sub>O<sub>62</sub>]<i><sup>n</sup></i><sup>-</sup> (<i>x</i> + <i>y</i> ≤ 8) related to the Dawson structure are reported. The mixed species are obtained
from the hexavacant anion [H<sub>2</sub>P<sub>2</sub>W<sub>12</sub>O<sub>56</sub>]<sup>12-</sup> by successive condensation and hydrolysis reactions. The strategy of
synthesis is mainly based on the steric control of hydrolysis reactions by the nature and the strength of the base,
the relative kinetic lability of molybdenum and tungsten in hydrolysis reactions, and the conservation of the framework
when vacant sites are refilled by new metal atoms. Rather good values of <sup>31</sup>P chemical shift variations can be
predicted by an additive model taking into account the contribution of substituting groups, depending on their
position in the structure. The influence of Mo/W and V/W substitutions on <sup>183</sup>W chemical shifts of the remaining W
atoms has been discussed and seems to be preferentially passed on through corner junctions.
2004-06-14 00:00:00
183 W chemical shifts
hydrolysis reactions
molybdenum
Dawson Type Heteropolyanions
P 2 Mo x V y W 18
synthesis
H 2 P 2 W 12 O 56
183 W NMR Structural Investigation
multinuclear NMR characterization
H 2 P 2 W 12 O 48
31 P chemical shift variations