- Isolation of niobium, tantalum, and titanium complex fluoride salts with alkali metal cations
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Fluoride and oxofluoride salts of niobium, tantalum, and titanium were isolated. They precipitated from aqueous solutions and upon washing of organic extracts with aqueous solutions of ammonium, potassium, and sodium salts. The compositions of the isolate
- Nikolaev,Kirichenko,Rys'kina
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p. 1070 - 1075
(2009/12/06)
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- Formation of the superoctahedral heteropolyanion [Ni(TaF6)6]4- through oxidation of tantalum with ammonium fluoride at the Monel-container wall
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A few single crystals of (NH4)4[Ni(TaF6)6] are obtained besides (NH4)[TaF6] as the main product of the reaction of (NH4)F with tantalum powder in an He-arc-welded Monel metal container at 400°C. The crystal structure (trigonal, R-3c (Nr. 167), Z = 6, a = 1723,0(2); c = 2166,6(2) pm; R1 = 0,0303, wR2 = 0,0609) contains the superoctahedral heteropolyanion [Ni(TaF6)6]4- and (NH4)+ ions; it may be recognized as a derivative structure of the K4CdCl6 type according to (NH4)4[Ni(TaF6)6]≡K 4[Cd(Cl)6].
- Schoening, Robert-A,Meyer, Gerd
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p. 1759 - 1762
(2008/10/09)
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