pretraga Na2GeF6

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5. On syntheses of single crystal complex fluorides of semimetal without solvents: lithium and sodium fluorogermanatesLi2[GeF6] and Na2[GeF6]

By Averdunk, F.; Hoppe, R.From Zeitschrift fuer Anorganische und Allgemeine Chemie (1990), 582, 111-20. Language: German, Database:CAPLUS

Colorless single crystals of Li2GeF6and Na2GeF6 were prepd. in a sealed copper tube by reaction of CuF2with Gepowder in presence of LiF or NaF without solvent. The crystal structure is detd. with R = 3.5 and Rw= 3.5% for Li2GeF6and R = 9.2 and Rw= 6.1% for Na2GeF6. The compds. crystallize isotypic to Na2SiF6in the space group P321, Z = 3.The Madelung part of the lattice energy is calcd. and compared with values of the binary components and Cs3GeF7.

~5 Citings

6. Acid-basic properties of fluorogermanates in melts of alkali metal nitrates

By Dratovsky, M.; Uchytilova, M.From Elektrokhimiya (1987), 23(11), 1566-70. Language: Russian, Database: CAPLUS

The acid-base behavior of Na2GeO3, GeO2, K4Ge2F10O, Na2GeF6, NaF, or K2Ge(IO3)6in NaNO3-KNO3melts wasstudied potentiometrically by using on O-sensitive electrode. Three new fluorogermanate anions identified by titrn. ofthese Lewis acids with Na2CO3or NaGeO3include GeF2O22-, Ge2F2O54-, and Ge4F6O98-.~0 Citings

7. Optical properties of some hexafluoro-complex compounds

By Levchishina, T. F.; Yamshchikov, E. F.From Izvestiya Akademii Nauk SSSR, Neorganicheskie Materialy (1982), 18(4), 673-5. Language: Russian, Database:CAPLUS

With the help of an improved immersion method the n was measured of microcrystals of Na2GeF6, Rb2GeF6, Cs2GeF6,Rb2SiF6, Cs2SiF6in the interval of 436-656 nm with an accuracy of (2-4) 10-4. A relation of the type n = A + Bv2wasfound. Crystals of Na2GeF6 and Rb2GeF6(hexagonal modification) were noted to have a weak birefringence.~0 Citings

8. Fusibility diagram of the sodium(1+), potassium(1+)hexafluorogermanate(2-), fluoride(1-) ternary reciprocal system

By Chernov, R. V.; Andriiko, A. A.From Ukrainskii Khimicheskii Zhurnal (Russian Edition) (1979), 45(10), 928-31. Language: Russian, Database:CAPLUS

The Na2GeF6-K2GeF3phase diagram and a planar projection of the Na+, K+GeF32-, F-diagram were constructed fromvisual-polythermal and DTA data. The stable diagonal is NaF-K2GeF6. Eutectics occur at 675, 670 and NaF 28, 26, KF49, 2.5, and K2GeF623, 71.5 mol. %. Thermal stability of fluorogermanate melts is higher than that of fluorosilicatemelts.~0 Citings

9. Kinetics and mechanism of the thermal decomposition of sodium hexafluorogermanate

By Andriiko, A. A.; Chernov, R. V.From Ukrainskii Khimicheskii Zhurnal (Russian Edition) (1979), 45(4), 298-303. Language: Russian, Database:CAPLUS

The decompn. of Na2GeF6 was studied by thermogravimetric methods. No liq. phase is visible during the decompn. toform GeF4and the ultimate, incongruently melting Na3GeF7. The apparent m.p. depends on the rate of heating. Kineticdata are interpreted in the light of stepwise loss of GeF4from a polymeric (Na2GeF6)15. The activation energy for theloss of the 1st mol. of GeF4is


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10. Fusibility diagrams of potassium hexafluorogermanate-potassium fluoride and sodium hexafluorogermanate-sodiumfluoride binary systems

By Andriiko, A. A.; Chernov, R. V.From Ukrainskii Khimicheskii Zhurnal (Russian Edition) (1979), 45(3), 217-20. Language: Russian, Database: CAPLUS

The m.ps. of K2GeF6and Na2GeF6 are 940-80. Exact detn. is hindered by their decompn. on heating to form GeF4.The literature values for these m.ps. are close to those of eutectics. K3GeF7m. congruently at 804. The eutectics, m.773 and 735, contain 25 and 76% KF resp. The Na3GeF7incongruently m. 650.~0 Citings

11. Rare earth metal oxysulfide phosphors

By Yamada, Hiromichi; Nakano, Masaki; Kano, Tsuyoshi; Yamamoto, HajimeFrom Jpn. Kokai Tokkyo Koho (1977), JP 52024170 A 19770223, Language: Japanese, Database: CAPLUS

Fe compd(s). selected from Na2SiF6, K2SiF6, Li2SiF6, (NH4)2SiF6, Na2GeF6, (NH4)2GeF6, (NH4)2TiF6, and NH4PF6

are used as a flux during the prepn. of rare earth oxysulfide-type phosphors by heating a mixt. consisting of rare earthmetal oxides (or compds. that can be converted to the oxides by heating) required to form {M1-x-y-zEuxSmy(Tb1-pPrp)z}2O3 (where M = Y, Gd, La, Lu; 0 z 1 10-4, 0 p 1; 0.024 x 0.04; 0.0005 y 0.009; but, the upperlimit for y decreases with increasing x; i.e. for x = 0.04 y 0.0025) and compds. required to form alkali metal sulfidesand/or polysulfides. Phosphor particles obtained by the method are relatively large and are planar, and hence, thephosphor coatings prepd. with these phosphors have improved luminosity. Thus, Na2SiF6 1.62 g was added to a mixt.consisting of Y2O3 18.86, Eu2O3 0.913, Sm2O3 0.136, Na2CO3 5.91, K3PO4 1.59, and S 5.91 g, the mixt. was thenheated 3 h at 1150, cooled, washed with H2O, 0.5% HCl, and with diionized water to give(Y0.9655Eu0.03Sm0.0045)2O2S phosphors: the av. grain size was 11.6 , vs. 4.5 for a control prepd. withoutNa2SiF6.~0 Citings

12. Rare earth oxysulfide type phosphors

By Yamada, Hiromichi; Nakano, Masaki; Kano, Tsuyoshi; Yamamoto, HajimeFrom Jpn. Kokai Tokkyo Koho (1976), JP 51142486 A 19761208, Language: Japanese, Database: CAPLUS

In prepg. rare earth oxysulfide-type phosphors by firing a mixt. of (M11-x-yEuxM2y)2O3 [where 0.001 x 0.1, 0 y 10-4, M1 = Y, Gd, La, or Lu, and M2 = Tb and/or Pr] with alkali metal sulfide-forming constituents, 1 compd(s). selectedfrom Na2SiF6, Li2SiF6, K2SiF6, Na2GeF6, (NH4)2GeF6, (NH4)2SiF6, (NH4)2TiF6, and NH4PF6 are added as a flux toincrease the grain size of the phosphors and to increase the brightness. The phosphors are useful in color televisioncathode-ray tubes. Thus, Na2SiF6 1.62 g was added to a mixt. of Y2O3 18.71, Eu2O3 1.28, Na2CO3 5.91, K3PO4 1.59,and S 5.91 g, the mixt. was then fired 3 h at 1150, the sintered products were ball-milled in an appropriate amt. of water,treated with dil. HCl soln., washed with distd. H2O, and dried at 120 to give (Y0.9577Eu0.0423)2O2S type phosphorswith av. particle size 11.6-vs. 4.5-for a control prepd. without adding Na2SiF6.~0 Citings

13. Nuclear magnetic resonance in hexafluorosilicates and hexafluorogermanates of alkali elements

By Gabuda, S. P.; Tychinskaya, I. P.; Lundin, A. G.From Radiospektrosk. Tverd. Tela (1967), 118. Language: Russian, Database: CAPLUS

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From Ref. Zh., Fiz. D. 1967, Abstr. No. 9D503. At 20 and -196, the N.M.R. spectra of 19F in the compds. Na2SiF6 andM2GeF6, where M = Li, Na, K, and Rb, was studied. Exptl. values for 2nd moments (S2) at -196 were (8.1 0.4) oe.2for all the compds. studied and agreed with theoretical calcns. of other investigators. The width and shape of spectra ofthe compds. studied (except the Na compd.) remained unchanged with increase in temp. The shape of the spectrum ofNa2SiF6 and Na2GeF6 changed from a wide unresolved singlet to an unresolved triplet with increase in temp. and S2decreased to 5.5 0.2 oe.2 This was due to reorientation of 33% of the octahedral ions of [SiF6]-or [GeF6]-around theiraxes. The S2 value for (NH4)2SiF6 at -196 was 11.5 0.5 oe.2 The increase in S2 of (NH4)2SiF6 as compared withS2 values of other compds. is explained by the contribution of protons of NH4 groups to the N.M.R. spectrum of 19F.~0 Citings

14. Fluorogermanates in systems of the M2GeF6-HF-H2O type

By Tychinskaya, I. I.; Nikolaev, N. S.From Zhurnal Neorganicheskoi Khimii (1963), 8, 734-7. Language: Unavailable, Database: CAPLUS

The systems K2GeF6-HF-H2O and Na2GeF6HF-H2O (isotherm 0) were studied by the method of isothermal soly. withinthe HF concn. range from 0 to 100%. The congruent character of dissoln. of the K and Na hexafluorogermanates in HFof various concns. was shown. Salts of the type M2GeF6(where M is K, Na, Cs, Li) dissolve in 100% HF withoutdecompn. The soly. of Li2GeF6is 2.51 wt. %, Na2GeF6 31%, K2GeF643.8%, and Cs2GeF655%. The soly. of thefluorogermanates in anhyd. HF increases with the ion radius of the cation. The possibility of the detn. of HF and thehexafluorogermanates of the alkali metals in a single sample by direct alkalimetric titration with phenol red was shown.~0 Citings

15. Structure of sodium fluosilicate and fluogermanate

By Cipriani, CurzioFrom Rendiconti della Societa Mineralogica Italiana (1955), 11, 58-77. Language: Unavailable, Database: CAPLUS

By the Patterson projection method the structure of the elementary lattice of Na2SiF6and Na2-GeF6(both prepd. by C.;crystallographic consts. checked) was found to be the same for both and different from that of the K salts. The structureis based on 3 octahedrons Si-F or Ge-F. Distances Na-F averaged 2.25 and 2.28 A., resp., for the 2 salts, distances Si-For Ge-F 1.88 and 1.91 A., resp. The elementary lattice is so represented as to have a layer structure with 4 layers, oneof Si (or Ge) and Na at z = 0, one of F at z = 0.25, one of Si (or Ge) at z = 0.5 and one of F at z = 0.75, approx.~2 Citings

16. Structure and crystallochemistry of Na2TiF6

By Cipriani, CurzioFrom Periodico di Mineralogia (1956), 24, 361-76. Language: Unavailable, Database: CAPLUS

cf. Rend. soc. mineralog, ital. 11, 58(1955). Hexagonal prismatic crystals with {1010} {1120} {1011}, a:c = 0.557: 1;optical consts.: = 1.412 0.001; = 1.419 0.001, for yellow light. Oscillation and Weissenberg diagrams give thespace group D3d3, the same as in Na2SiF6and Na2GeF6. (loc. cit.); a0= 9.20 0.01, c0= 5.13 0.01, mol. vol. 376 2cu. A., Z = 3 mols. Na2TiF6, d. 2.78. At. coordinates detd. were: Ti(I) in 1a 0, 0, 0; Ti(II) in 2d 1/3, 2/3, z(z = 1/2); Na in 6gx, 0, 0 (x = 1/3); F(I) in 6i x1, x1, z1(x1= 0.10; z1= 0.23); F(II) in 6i x2, x2, z2(x2= 0.24; z2= 0.77); F(III) in 6i x3, x3, z3(x3=0.42; z = 0.23). Distances Ti(I)-F(I) 1.98 A.; Ti(II)-F(II) 2.04 A.; Ti(II)-F(III) 1.96 A.; Na-F (av.) 2.33 0.08 A. Expts. to

prep. cryst. solns. of Na2TiF6and Na2SiF6made evident that there is only a limited miscibility; it was esp. evident from x-ray precision measurements of a0and c0. The miscibility gap extends from 18 to 97 mol. % Na2TiF6(in dil. HF assolvent, and temp. = 90). In the system Na2TiF6-Na2GeF6 the miscibility is probably complete, with a continuous seriesof cryst. solns.~0 Citings

17. Complex fluorides. III. Lattice constants of complex fluorides of lithium or sodium and quadrivalent elements

By Cox, B.From Journal of the Chemical Society (1954), 3251-2. Language: Unavailable, Database: CAPLUS

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