“…Two W atoms of distorted octahedral geometry are linked by the O atom with site symmetry 4/mmm, forming the linear W-O-W group. The W-O distance, 1.871 (1) A, is longer than the 1.819 A in NazWO4 (Okada, Morikawa, Marumo & Iwai, 1974) but shorter than the W-O(bridging) distance (1.93 A) in [W2OI~(H20)2] 2- (Einstein & Penfold, 1964). A similar lengthening of the metal-oxygen bond going from tetrahedral MO~-to octahedral oxygen-bridged compounds was found for Re complexes, viz.…”
Abstract. KgWzOClt0, M.W. 894.6, tetragonal, 14/mmm, a=7.132 (2), c= 17.648 (5) A, V=897"7 A a, dx = 3"31 g cm -a, Z= 2, F(000) = 804. Full-matrix leastsquares refinement yielded a final R=0.038. The W-O-W bridge is linear with W-O= 1-871 (1) A.
“…Two W atoms of distorted octahedral geometry are linked by the O atom with site symmetry 4/mmm, forming the linear W-O-W group. The W-O distance, 1.871 (1) A, is longer than the 1.819 A in NazWO4 (Okada, Morikawa, Marumo & Iwai, 1974) but shorter than the W-O(bridging) distance (1.93 A) in [W2OI~(H20)2] 2- (Einstein & Penfold, 1964). A similar lengthening of the metal-oxygen bond going from tetrahedral MO~-to octahedral oxygen-bridged compounds was found for Re complexes, viz.…”
Abstract. KgWzOClt0, M.W. 894.6, tetragonal, 14/mmm, a=7.132 (2), c= 17.648 (5) A, V=897"7 A a, dx = 3"31 g cm -a, Z= 2, F(000) = 804. Full-matrix leastsquares refinement yielded a final R=0.038. The W-O-W bridge is linear with W-O= 1-871 (1) A.
“…The dimeric moiety [M 2 O 2 (µ-O 2 ) 2 (O 2 ) 2 ] is a building block for these five anions. To the best of our knowledge, it has not been observed in peroxotungsten complexes with oxo, [15] oxalate [16] and carbonate [17] or in oxoperoxomolybdates [18,19] with molybdate as assembling ligands, [{MoO (O 2 6-. Complexes with [20] and without [20,21] w-, x = 1-4.…”
“…Transformation of K 2 [W 2 O 3 (O 2 ) 4 (H 2 O) 2 ]·2H 2 O (4) into 1: The dimeric peroxotungstate 4 (0.50 g, 0.7 mmol), prepared by the published method,23 was dissolved in 5 mL of water. Citric acid (0.34 g, 1.5 mmol) was added to this solution followed by a small amount of 30 % H 2 O 2 .…”
Section: Methodsmentioning
confidence: 99%
“…To better understand these catalytic processes, a more detailed characterization of peroxotungstates is necessary. It appears that [W(O 2 ) 4 ] 2– predominates at high pH (>7) and in the presence of excess H 2 O 2 ,22 whereas at intermediate pH (1.3–7.0) the dimer [W 2 O 3 (O 2 ) 4 (H 2 O) 2 ] 2– is the major species,23 and at lower pH the solution become unstable and lose oxygen 24. Although other peroxotungstates have also been observed in the solid state25–27 and solution,28,29 the key to stabilizing peroxotungstates is to incorporate a ligand that can effectively coordinate to tungsten.…”
Section: Introductionmentioning
confidence: 99%
“…However, unlike peroxomolybdates( VI ), which have been investigated extensively,40–47 fewer peroxotungstate species with other ligands have been structurally reported. Known compounds include dimeric oxalate and tetranuclear carbonate complexes such as M 2 [WO(O 2 ) 2 (C 2 O 4 )] (M = K + , NH 4 + )48,49 [( n ‐C 4 H 9 ) 4 N] 2 [W 2 O 2 (O 2 ) 4 (C 2 O 4 )],50 K 6 [W 4 O 8 (O 2 ) 6 (CO 3 )] · 6H 2 O,51 or isoperoxotungstateslike K 2 [W(O 2 ) 4 ],22 K 2 [W 2 O 3 (O 2 ) 2 (H 2 O) 2 ] · 2H 2 O,23 (Me 3 CNH 3 ) 4 [W 4 O 12 (O 2 ) 2 ],25 [( n ‐C 4 H 9 ) 4 N] 2 [W 4 O 6 (O 2 ) 6 (OH) 2 (H 2 O) 2 ] · H 2 O,26 and Cs 2 (CN 3 H 6 ) 3 [(C 2 H 5 ) 2 NH 2 ][W 7 O 22 (O 2 ) 2 ] · 3H 2 O 27…”
The reaction of potassium tungstate with the biologically relevant ligands citric and tartaric acid, in the presence of hydrogen peroxide, was investigated to discover the effect of pH variation on the product pattern.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.