Synthesis and structure of dititanium-containing 10-tungstogermanate [{γ-GeTi2W10O36(OH)2}2(μ-O)2]8−

Recent Advances of Ti/Zr-Substituted Polyoxometalates: From Structural Diversity to Functional Applications

“…The polyoxoanion consisted of a dimeric anhydride form of two [α-1,2-PW 10 Ti 2 O 40 ] 7− Keggin units linked with two Ti-O-Ti bonds [44]. Similar structures have also been reported by Mizuno and Wang's groups, respectively [45,46] (Figure 3g) [48]. Subsequently, they synthesized a similar structure using mono-lacunary Dawson precursor K 10 [α 2 -P 2 W 17 O 61 ]•23H 2 O [49].…”

Transformation of Tri-Titanium(IV)-Substituted α-Keggin Polyoxometalate (POM) into Tetra-Titanium(IV)-Substituted POMs : Reaction Products of Titanium(IV) Sulfate with the Dimeric Keggin POM Precursor under Acidic Conditions

“…We can reveal only the molecular structure of the POM, but not the crystal structure. These features are too common in the POM crystallography [9,10,11,12,13,14,15,16,17,18]. …”

“…Site-selective substitution of the W VI atoms in POMs with Ti IV atoms is particularly interesting, because of formation of the multicenter active sites with corner- or edge-sharing TiO 6 octahedra and, also, generation of oligomeric species through Ti-O-Ti bonds [9,10,11,12,13,14,15,16,17,18]. A number of catalytic reactions of titanium(IV)-containing POMs have also been reported so far [19,20,21].…”

“…Di-Ti IV -substituted γ-Keggin silicotungstate and germanotungstate, i.e. , [{γ-SiTi 2 W 10 O 36 (OH) 2 } 2 O 2 ] 8- [14] and [{γ-GeTi 2 W 10 O 36 (OH) 2 } 2 O 2 ] 8- [15], have been also prepared as a dimeric species, while di-Ti IV -1,5-substituted β-Keggin POM has been isolated as a tetrameric species, [{β-Ti 2 SiW 10 O 39 } 4 ] 24- [16]. In addition, the cyclic tri-Ti IV -substituted Keggin trimers such as [(α-Ti 3 PW 9 O 38 ) 3 (PO 4 )] 18- [17], [(α-Ti 3 SiW 9 O 37 OH) 3 (TiO 3 (OH 2 ) 3 )] 17- [17], and {K[(Ge(OH)O 3 ) (GeW 9 Ti 3 O 38 H 2 ) 3 ]} 14- [18] have been recently reported.…”

Structural Chemistry of Titanium (IV) Oxo Clusters, Part 2: Clusters without Carboxylate or Phosphonate Ligands

“…In this case the Ti 4 unit remains planar. Not surprisingly, this structure type is found for derivatives substituted by two polyoxometallate (POM) "ligands", namely [Ti 4 O 2 (OH) 4 (EW 10 O 34 ) 2 ] 8À (E = Si, [70] Ge [71] ). The clusters consist of two [Ti 2 (OH) 2 (EW 10 O 34 )] 2À units which are interconnected by two μ 2 -O.…”