New Strategies for the Generation of Large Heteropolymetalate Clusters: The β‐B‐SbW₉ Fragment as a Multifunctional Unit

Abstract

Abstract:Proceeding from the x-B-SbW,O,, fragment 1, various novel large heteropolyanions ([Na,Sb,W,,O, 3Z(H,0),]22~~ (2), [Sb,W,,0,,(OH),]'2~ ( 3 ) and (4); M"' = Fe3+, Co", Mn''. Ni") have been obtiiined in crystalline form by systematic synthesis. Their unexpected structures have been studied by X-ray diffraction: 2, 3 and 4 contain /j-SbW,l units connected to each other by Sb3 ions, WOJW0,OH groups. and WO,/M"+(H,O), groups. respectively. Structural details and especially the systematic synthesis strategy for the formation of these interesting polytungstates are discussed in order to explain the unusual behaviour of 1 in aqueous solulion under different rcaction conditions.

The Hybrid Organic‐Inorganic 2‐D Material (CsNa2[{Sn(CH3)2}3(H2O)4(β‐XW9O33)]·7H2O)∞ (X = AsIII, SbIII) and Its Solution Properties

“…The molecular formulae and charges of 1a and 2a are supported by bond-valence calculations, which indicate that all terminal oxygen atoms bound to the tin atoms are diprotonated. [15] Close inspection of 1a and 2a indicates that the CϪSnϪC bond angles are significantly smaller than 180°, indicating that the interior methyl groups still experience some degree of repulsion (see Figure 1) [16,17] This is in complete agreement with the synthetic conditions for 1a and 2a, which were isolated at pH 3. The (β-AsW 9 O 33 ) fragment has so far only been observed in two different polyoxoanion structures.…”

“…[17,20] All other reagents were used as purchased without further purification. All elemental analyses were performed by Kanti Labs Ltd. in Mississauga, Canada.…”

Polyoxometalates: Powerful Catalysts for Atom‐Efficient Cyclopropanations

“…[47] As each cobalt cation in the latter complex bears three water molecules instead of a single one, its catalytic activity could be improved, as already suggested. [47][48][49] One asset of multi-vacant POMs is their ability to coordinate several active metallic sites, so that synergistic effects could arise, provided that they are not too distant from each other. We thus included the study of…”

“…(3), [47] initially prepared as a sodium salt has been transferred in dichloroethane as already described. Conversely, the availability of 4 as a tetrabutylammonium salt (TBA) 4 [50] allowed us to solubilise it directly in the reaction solvent.…”

Tetra-cobalt-substiituted Dimeric Tungstoantimonate: Na10[Co4(H2O)10(B- -SbW9O33)2]�36H2O

“…The precursor Na 9 [SbW 9 O 33 ]·19.5H 2 O was prepared according to the literature [15] and its purity was confirmed by infrared spectroscopy. All other reagents were used as purchased without further purification.…”