A sandwich-type aluminium complex composed of tri-lacunary Keggin-type polyoxotungstate: synthesis and X-ray crystal structure of [(A-PW9O34)2{W(OH)(OH2)}{Al(OH)(OH2)}{Al(μ-OH)(OH2)2}2]7−

Abstract

The synthesis and molecular structure of a dimeric aluminium complex composed of tri-lacunary α-Keggin polyoxometalate is described. The polyoxometalate, K(6)Na[(A-PW(9)O(34))(2){W(OH)(OH(2))}{Al(OH)(OH(2))}{Al(μ-OH)(OH(2))(2)}(2)]·19H(2)O (KNa-1), afforded by the reaction in water of a tri-lacunary Keggin polyoxotungstate with excess aluminium nitrate, followed by crystallization from water, was obtained as analytically pure, homogeneous, colorless crystals. The compound KNa-1 was characterized by elemental analysis, TG/DTA, FT-IR, solution NMR ((31)P, (27)Al, and (183)W), and X-ray crystallography. The single-crystal X-ray structure analysis revealed that two 6-coordinate aluminium ions linked with two bridging hydroxyl groups and four water molecules, i.e., [Al(III)(2)(μ-OH)(2)(OH(2))(4)](4+); a unit of a 6-coordinate tungsten ion linked with a hydroxyl group and a water molecule, i.e., [W(OH)(OH(2))](5+); a unit of a 6-coordinate aluminium ion linked with a hydroxyl group and a water molecule, i.e., [Al(OH)(OH(2))](2+), were sandwiched between two tri-lacunary α-Keggin polyoxotungstates, resulting in an overall C(s) symmetry.

A Novel Photocatalytic System Constructed Using Eosin Y, Titanium Dioxide, and Keggin-Type Platinum(II)- and Aluminum(III)-Coordinated Polyoxotungstates for Hydrogen Production from Water Under Visible Light Irradiation

“…Compounds Cs-Pt-1, K-Al-1, TMA-Al-2, KNa-Al-3, KAl-5, and K 8 [a-SiW 11 O 39 ]Á17H 2 O were synthesized using literature methods [9,[11][12][13][14][15]. Compound TMA-Al-4 was synthesized analogously to the published method for K 7 [a 2 -P 2 W 17 {Al(OH 2 )}O 61 ]Á14H 2 O [12]; the synthetic details and characterization results are shown in the Supporting Information.…”

Synthesis, Structure, and Characterization of In10-Containing Open-Wells–Dawson Polyoxometalate

“…Synthetic and structural studies of group 13 ion-containing POMs provide informative and definitive molecular models of group 13 metal clusters in solution. However, among all the Al-, Ga-, and In-containing POMs, formed by the substitution of several tungsten ions in the parent POMs with trivalent group 13 ions [28,[33][34][35][36][37][38][39][40], few well-characterized In-containing POMs have been reported to date [41][42][43]. Thus, In-containing POMs are intriguing target compounds from both a synthetic and a structural point of view.…”

Synthesis, X-ray Crystal Structure, and Photochromism of a Sandwich-Type Mono-Aluminum Complex Composed of Two Tri-Lacunary α-Dawson-Type Polyoxotungstates

“…Although various techniques for functionalization of polyoxometalates have been reported, the synthetic technology of introducing metal ions into vacant sites using lacunary polyoxometalates as inorganic ligands is an effective technique for constructing stable and well-defined active metal centers. In terms of polyoxometalates containing aluminum ions as heteroatoms, various aluminum compounds have been synthesized and structurally characterized [10,11,12,13,14,15,16,17]. Although some aluminum-containing polyoxometalates, e.g., [γ-SiW 10 O 36 {Al(OH 2 )} 2 (μ-OH) 2 ] 4− [10], [(A-PW 9 O 34 ) 2 {W(OH)(OH 2 )}{Al(OH)(OH 2 )}{Al(μ-OH)(OH 2 ) 2 } 2 ] 7− [11], [α-PW 11 {Al(OH 2 )}O 39 ] 4− [11], and [α 2 -P 2 W 17 {Al(OH 2 )}O 61 ] 7− [11], and [Al 4 (H 2 O) 10 (β-AsW 9 O 33 H) 2 ] 4− [12], have been used as Lewis acids and oxidation catalysts, examples of structurally characterized aluminum complexes with polyoxometalate ligands remain rare, and their properties and activities are unknown.…”