Structural Retention of Decatungstates upon Photoreduction

Abstract

The crystal structures of oxidized and photoreduced decatungstates are compared. Three specimens of decatungstate complexes were prepared in mixed solvents of H2O–CH3CN and were characterized by X-ray diffraction. Unit cell parameters are as follows: (C6H16N)4[W10O32]·2CH3CN; DECA Mr=2841.4, monoclinic, P21⁄n, a=14.617(2), b=17.783(3), c=11.755(2) Å, β=100.27(2)°, V=3006.5(9) Å3, Z=2; (C6H16N)4[H1.5W10O32]·8H2O; RED1 Mr=2905.4, monoclinic, P21⁄n, a=15.902(3), b=12.233(2), c=15.673(4) Å, β=93.76(2)°, V=3042(1), Å3 Z=2; Na4[H1.8W10O32]·14H2O; RED2 Mr=2696.7, monoclinic, C2⁄m, a=16.123(5), b=12.636(3), c=12.168(4) Å, β=117.40(2)°, V=2202(1) Å3, Z=2; There is no obvious change in the anion frame among the three decatungstate complexes. Photoreduced decatungstates may coordinate protons which neutralize excess charge injected into anions. It is concluded that the structure of W10O32 is not largely altered up to two-electron reduction.

Synthesis and characterization of dicarboranylmethylammonium polyoxometallates

“…12). The intermolecular distances and angles of the [W 10 O 32 ] 4-fall within the ranges previously found for this isopolyanion [34][35][36] .…”

DFT Calculations of the 183W NMR Chemical Shifts in Reduced Polyoxotungstates

“…We should bear in mind that when an anion is reduced, it "swells" because the bond lengths increase. According to the X-ray structure determination of the oxidized and reduced species [30] of the decatungstate, both types of WO 6 octahedron increase in size slightly, which is confirmed by the structures computed for oxidized and reduced anions. The geometry changes most in the belt octahedra (see the bond lengths in Table 4).…”

“…some bonds are elongated). [15,[27][28][29][30] Thus, in all cases, for both the parent oxidized POM and its reduced counterparts, the structures used were the optimized ones before and after the two electrons had been introduced. This anion is a derivative of the Lindqvist anion that contains one tungsten atom in the formal oxidation state 2+ with an NO group in place of the terminal oxygen atom.…”

Assembly of Pure Silver‐Tungsten‐Oxide Frameworks from Nanostructured Solution Processable Clusters and Their Evolution into Materials with a Metallic Component

“…Indeed, the presence of the organic templating TEAH cations are crucial in directing the assembly of the {W 19 } archetype, see Figure , since in the absence of TEAH (e.g. with inorganic cations) only the well known [W 10 O 32 ] 4− unit20 can be obtained.…”