Abstract
The Rb- and Sr-exchanged forms of ivanyukite have been obtained and structurally characterized. The chemical formulas derived from the electron microprobe data are as follows: the Rb-exchanged form (Na0.10K0.07Ca0.15Sr0.05Rb1.81Ba0.02)Σ = 2.20[(Ti3.65Nb0.19Fe0.05Mn0.01)Σ = 3.90O2.07/(OH)1.93(Si2.98Al0.02)Σ = 3.00 O12] · 3.61H2O; the Sr-exchanged form (K0.03Sr0.81Ca0.04Ba0.07)Σ = 0.95[(Ti3.74Nb0.19Fe0.03)Σ = 3.96] [O1.83/(OH)2.17](Si2.99Al0.01)Σ = 3.00O12) · 7H2O. The structures of the Rb- and Sr-exchanged forms of ivanyukite have been solved and refined using the least squares method. The structures are based on a mixed three-dimensional octahedral-tetrahedral framework of the pharmacosiderite type with channels occupied by Rb+ and Sr2+ cations and water molecules. The Rb+ cations in the Rb-exchanged form are 12-coordinated, whereas the Sr2+ cations in the Sr-exchanged form are 9- or 7-coordinated. The statistical investigation of the geometric parameters of the pharmacosiderite-type titanosilicates showed that symmetry changes are associated with the interactions of extraframework cations with the O atom of the Ti4(O,OH)4 clusters of the titanosilicate framework. The relationship between the unit-cell parameters in titanosilicates of the pharmacosiderite type and the structural geometric parameters of the titanosilicate framework has been proved by the use of multiple regression equations.
Similar content being viewed by others
References
Behrens, E.A. and Clearfield, A., Titanium Silicates, M 3HTi4O4(SiO4)3·4(H2O) (M = Na+, K+), with Three-Dimensional Tunnel Structures for the Selective Removal of Strontium and Cesium from Wastewater Solutions, Microporous Mater., 1997, vol. 11, pp. 65–75.
Behrens, E.A., Poojary, D.M., and Clearfield, A., Syntheses, X-Ray Powder Structures and Preliminary Ion-Exchange Properties of Germaniuim Substituted Titanosilicate Pharmacosiderites: HM 3(AO)4(BO4)3 · 4(H2O) (M = K, Rb, Cs; A = Ti, Ge; B = Si, Ge), Chem. Mater., 1998, vol. 10, pp. 959–967.
Behrens, E.A., Poojary, D.M., and Clearfield, A., Syntheses, Crystal Stuctures, and Ion-Exchange Properties of Porous Titanosilicates, HM 3Ti4O4(SiO4)3 · 4(H2O) (M = H+, K+, Cs+), Structural Analogues of the Mineral Pharmacosiderite, Chem. Mater., 1996, vol. 8, pp. 1236–1244.
Chapman, D.M. and Roe, A.L., Synthesis, Characterization and Crystal Chemistry of Microporous Titanium-Silicate Materials, Zeiolites, 1990, vol. 10, pp. 730–737.
Dadachov, M.S. and Harrison, W.T.A., Synthesis and Crystal Structure of Na4[(TiO)4(SiO4)3] · 6H2O, a Rhombohedrally Distorted Sodium Titanium Silicate Pharmacosiderite Analogue, J. Solid Chem., 1997, vol. 134, pp. 409–415.
Harrison, W.T.A., Gier, T.E., and Stucky, G.D., Single-Crystal Structure of Cs3HTi4O4(SiO4)3 · 4(H2O), a Titanosilicate Pharmacosiderite Analog, Zeolites., 1995, vol. 5, pp. 408–412.
Sheldrick, G.M., SHELX-97 Programs for Crystal Structure Analysis, Institute of Inorganic Chemistry, University of Göttingen, 1997.
Spiridonova, D.V., Krivovichev, S.V., Ivanyuk, G.Yu., and Yakovenchuk, V.N., Crystal Structure of Ivanyukite-Na-T. in Mineralogicheskie muzei-2008 (Proceedings of the International Symposium on Mineralogical Museums-2008), St. Petersburg, 2008, pp. 144–146.
Tripathi, A., Medvedev, D.G., Delgado, J., and Clearfield, A., Optimizing Cs-Exchange in Titanosilicate with the Mineral Pharmacosiderite Topology: Framework Substitution of Nb and Ge, J. Solid State Chem., 2004, vol. 177, pp. 2903–2915.
Xu, H., Navrotsky, A., Nyman, M., and Nenoff, T.M., Thermochemistry of Microporous Silicotitanate Phases in Na2O-Cs2O-SiO2-TiO2-H2O System, J. Mater. Res., 2000, vol. 15, pp. 815–823.
Xu, H., Navrotsky, A., Nyman, M., and Nenoff, T.M., Crystal Chemistry and Energetics of Pharmacosiderite-Related Microporous Phases in the (K2O)-(Cs2O)-(SiO2)-(TiO2)-(H2O) System, Micropor. Mesopor. Mat., 2004, vol. 772, pp. 209–218.
Yakovenchuk, V.N., Nikolaev, A.P., Selivanova, E.A., Pakhomovsky, Ya.A., Korchak, J.A., Spiridonova, D.V., Zalkind, O.A., and Krivovichev, S.V., Ivanyukite-Na-T, Ivanyukite-Na-C, Ivanyukite-K, and Ivanyukite-Cu: New Microporous Titanosilicates from the Khibiny Massif (Kola Peninsula, Russia) and Crystal Structure of Ivanyukite-Na-T, Am. Mineral., 2009, vol. 94, pp. 1450–1458.
Yakovenchuk, V.N., Selivanova, E.A., Ivanyuk, G.Yu., Pakhomovsky, Ya.A., Spiridonova, D.V., and Krivovichev, S.V., First Natural Pharmacosiderite-Related Titanosilicates and Their Ion-Exchange Properties, in Minerals as Advanced Materials, I. Krivovichev S.V., Ed., Springer: Berlin, 2007, pp. 27–35.
Yakubovich, O.V., Massa, V., and Dimitrova, O.V., A Novel Representative {[Rb1.94(H2O,OH)3.84](H2O)0.1} {Al14(OH)4[RO4]3} of the Pharmacosiderite Structural Type, Kristallografiya, 2008, vol. 53, no. 3, pp. 442–449 [Crystallogr. Rep. (Engl. Transl.), 2008, vol. 53, no. 3, pp. 409–417].
Author information
Authors and Affiliations
Corresponding author
Additional information
Original Russian Text © D.V. Spiridonova, S.V. Krivovichev, V.N. Yakovenchuk, Ya.A. Pakhomovsky, 2010, published in Zapiski RMO (Proceedings of the Russian Mineralogical Society), 2010, No. 5, pp. 79–88.
Rights and permissions
About this article
Cite this article
Spiridonova, D.V., Krivovichev, S.V., Yakovenchuk, V.N. et al. Crystal structures of the Rb- and Sr-exchanged forms of ivanyukite-Na-T . Geol. Ore Deposits 53, 670–677 (2011). https://doi.org/10.1134/S1075701511070208
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S1075701511070208