Synthesis, Magnetism, and Electrochemistry of the Ni₁₄- and Ni₅-Containing Heteropolytungstates [Ni₁₄(OH)₆(H₂O)₁₀(HPO₄)₄(P₂W₁₅O₅₆)₄]^34–and [Ni₅(OH)₄(H₂O)₄(β-GeW₉O₃₄)(β-GeW₈O₃₀(OH))]^13–

Abstract

The two Ni(2+)-containing heteropolytungstates [Ni14(OH)6(H2O)10(HPO4)4(P2W15O56)4](34-) (Ni14) and [Ni5(OH)4(H2O)4(β-GeW9O34)(β-GeW8O30(OH))](13-) (Ni5) have been successfully synthesized in aqueous, basic media under conventional reaction conditions, and they were characterized by single-crystal X-ray diffraction, IR spectroscopy, thermogravimetric and elemental analyses, electrochemistry, and magnetic studies. The cyclic voltammetry (CV) patterns of Ni14 and Ni5 showed chemically reversible multielectronic waves for slow scan time scales. For Ni14, an important acidity inversion effect between its reduced forms was observed. Magnetic studies revealed dominant ferromagnetic interactions among the nickel(II) ions in both polyanions.

Lanthanide-Connecting and Lone-Electron-Pair Active Trigonal-Pyramidal-AsO3 Inducing Nanosized Poly(polyoxotungstate) Aggregates and Their Anticancer Activities

“…2g) was also synthesized by Kortz and collaborators, which can be viewed as a combination of a trilacunary [β-GeW 9 O 34 ] 10− and a tetralacunary [β-GeW 8 O 30 (OH)] 9− linked by a [Ni 5 (OH) 4 (H 2 O) 4 ] 6+ core (Fig. 2h)36. The remarkable differences between 1c (Fig.…”

[{Ni4(OH)3AsO4}4(B‐α‐PW9O34)4]28−: A New Polyoxometalate Structural Family with Catalytic Hydrogen Evolution Activity

“…Multi‐nickel clusters stabilized by POMs have also been studied (e.g., {Ni 6 W 24 }8s {Ni 7 W 19 },8t {Ni 8 W 18 },8u {Ni 9 W 18 },8u {Ni 9 W 27 },8v {Ni 12 W 35 },8w {Ni 14 W 60 },8x). To date, the largest number of Ni ions incorporated into a single POM cluster was 14 8x. Yang and co‐workers reported a series of {Ni 20 }‐ to {Ni 40 }‐containing POMs,9 prepared under hydrothermal conditions using organic amines, which contained organic ligands.…”

“…Representative examples of these structurally, catalytically, and magnetically interesting multinuclear ( n ≥6) TMSPOMs include {Mn 6 W 18 },2a {Mn 6 W 24 },8a {Mn 14 W 36 },8b {Mn 14 W 48 },8c {Fe 6 W 24 },8d {Fe 9 W 12 },8e {Fe 9 W 24 },2b {Fe 13 W 36 },8f, g {Fe 16 W 48 },8h {Fe 28 W 48 },8i {Co 6 W 24 },8j–l {Co 7 W 25 },8m {Co 9 W 27 },8n {Co 16 W 36 },2c, 5j, 8o {Cu 6 W 18 },8p {Cu 14 W 36 },8q and {Cu 20 W 48 } 8r. Multi‐nickel clusters stabilized by POMs have also been studied (e.g., {Ni 6 W 24 }8s {Ni 7 W 19 },8t {Ni 8 W 18 },8u {Ni 9 W 18 },8u {Ni 9 W 27 },8v {Ni 12 W 35 },8w {Ni 14 W 60 },8x). To date, the largest number of Ni ions incorporated into a single POM cluster was 14 8x.…”

Nitrate and Nitrite Electrocatalytic Reduction at Layer-by-Layer Films Composed of Dawson-type Heteropolyanions Mono-substituted with Transitional Metal Ions and Silver Nanoparticles

“…The accumulation of transitional ion centers within the HPA cage is associated with an enhancement of the catalytic properties of these atoms, with the complementary advantage to generate highly reduced products by the electrons from the reduced W-O framework as electronic storage [31]. The favorable effect on NRR catalysis of accumulation of substituent ion within the same molecule has been shown for sandwich-type Cu 2+ - [52] and Ni 2+ -multisubstituted HPA [52,57] in comparison with monosubstituted derivatives. Starting with the reduction to nitrite by the HPA, the whole reaction goes through nitric oxide (NO) [55] down to ammonia [48].…”