Decatantalate—The Last Member of the Group 5 Decametalate Family

Abstract

A tetra-n-butylammonium (TBA) salt of [Ta10O28](6-) was synthesized by heating TBA6[H2Ta6O19] in toluene for a prolonged period. X-ray structural analysis of TBA6[Ta10O28]·6H2O revealed that the anion has the decametalate structure and is isostructural with the decavanadate and decaniobate anions [a = 15.8517(8) Å, b = 19.364(1) Å, c = 21.935(1) Å, β = 93.638(1)°, V = 6719.4(6) Å(3), Z = 2, and space group P2(1)/n at 292(2) K].

Characterization of decavanadate and decaniobate solutions by Raman spectroscopy

“…It also does not escape our attention that a similar approach could be used to detail the relationship between [Ta 6 , the latter being isolated only recently. 42 …”

Coordination-Induced Condensation of [Ta6O19]8–: Synthesis and Structure of [{(C6H6)Ru}2Ta6O19]4–and [{(C6H6)RuTa6O18}2(μ-O)]10−

“…For example, two polymorphs of (Bu 4 N)4 [(NbW 5 O 18 ) 2 O] exist, with different crystal packing features, with either strictly linear Nb−(μ-O)−Nb units, or eclipsed conformation of the {NbW 5 O 18 } units similarly to 1. In contrast, the M−(μ-O)−M angle deviates from 180°in isostructural compounds (Bu 4 N) 4 [(TiM 5 O 18 ) 2 O]·2MeCN, M = Mo, W.…”

Titanium‐Substituted Polyoxotantalate Clusters Exhibiting Wide pH Stabilities: [Ti2Ta8O28]8− and [Ti12Ta6O44]10−

“…This result indicates that Ti‐disubstitution is preferred to Ti‐monosubstitution in the decatantalate structure, and it also denotes a departure from niobate chemistry. Additionally, we note that the decatantalate ion was undetectable by ESI‐MS in the synthesis attempts without Ti sources, suggesting that decatantalate could only be isolated in non‐aqueous solution, as previously synthesized by Yagasaki et al . However, the aqueous synthesis of Ti 2 Ta 8 in our study suggests that Ti substitution engenders stability to the decatantalate‐type structure in aqueous solution…”

“…Less well developed are the niobates, yet there are still dozens of niobate clusters that are stable in solution, including substituted polyoxoniobates discovered during the last decade . In contrast, among the polyoxotantalates, only the hexatantalate ion (Ta 6 ) and transition‐metal coordinated (capped) Ta 6 are known, in addition to the recently reported decatantalate (Ta 10 ) through condensation of Ta 6 in non‐aqueous solution . The chemistries of polyoxoniobate and polyoxotantalate ions are expected to be broadly similar, but differences in the properties of hexaniobate and hexatantalate ions have been recently demonstrated…”

“…[2] In contrast, among the polyoxotantalates, only the hexatantalate [3] ion (Ta 6 )a nd transition-metal coordinated (capped) Ta 6 are known, [4] in addition to the recently reported decatantalate (Ta 10 )t hrough condensation of Ta 6 in non-aqueous solution. [5] The chemistries of polyoxoniobate and polyoxotantalate ions are expected to be broadly similar,b ut differences in the properties of hexaniobate and hexatantalate ions have been recently demonstrated. [6] In light of the synthetic success of Ti-substituted polyoxoniobates, [7] we envisioned that as imilar strategy for Ti-substitution in polyoxotantalate ions may be possible.…”