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The sodium potassium citrato oxotungstate(VI) dimer, Na 4K 2〔W 2O 5|(cit) 2〕·11H 2O (H 4cit = citric acid) was obtained by the reaction of sodium tungstate(VI) and excess potassium citrate monobasic (KH 3cit) in neutral solution. The crystal data for the title compound: monoclinic, C 12 H 30 K 2Na 4W 2O 30 , M r =1192.21, space group P2 1/n, a=17.427(4), b=10.022(2), c=18.637(3) , β=92.62(1)°, V=3252(2) 3, Z=4, D c =2.435 g/cm 3, μ( Mo Kα )=76.38 cm -1 , F( 000)=2288. The structure was refined to R =0.0434 for 6327 independent observed reflections with I>3σ(I) . The complex anion contains a quasi centrosymmetric (O 2W)O b(WO 2) core with a bent bridging oxo group 〔W-O b-W 175.0(4)°〕. Each citrate as tridentate ligand coordinates to a tungsten atom through the alkoxy, α carboxyl, and one β carboxyl group, while the other β carboxyl group remains uncoordinated. Principal dimensions are: W-O b 1.883(6) , (W=O t)av 1.715(6) , W-O (alkoxy) 1.959(6) , W-O ( α carboxy) 2.176(6) and W-O ( β carboxy) 2.231(6) . The tungsten atom is located in a distorted octahedron environment.
The sodium potassium citrato oxotungstate (VI) dimer, Na 4K 2 [W 2 O 5 | (cit) 2] · 11H 2O (H 4 cit = citric acid) was obtained by the reaction of sodium tungstate (VI) and excess potassium citrate The crystal data for the title compound: monoclinic, C 12 H 30 K 2Na 4W 2O 30, M r = 1192.21, space group P2 1 / n, a = 17.427 (4), b = 10.022 (2), c = 18.637 (3) β, β = 92.62 (1) °, V = 3252 (2) 3, Z = 4, D c = 2.435 g / cm 3, μ (Mo Kα) = 76.38 cm -1, F (000) = 2288. The structure was refined to R = 0.0434 for 6327 independent observed reflections with I> 3σ (I). The complex anion contains a quasi-centrosymmetric (O 2W) O b Each citrate as tridentate ligand coordinates to a tungsten atom passes through the alkoxy, a carboxyl, and one beta carboxyl group, while the other beta carboxyl group remains uncoordinated. Principal dimensions are : WO b 1.883 (6) , (W = O t) av 1.715 (6) WO (alkoxy) 1.959 6 WO 6) . The tungsten atom is located in a distorted octahedron environment.