Synthesis and Structure of Low-Dimensional Gallium Fluorodiphosphates Seen during the Crystallization of the Three-Dimensional Microporous Gallium Fluorophosphate ULM-3
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- 作者：Franck Millange ; Richard I. Walton ; Nathalie Guillou ; Thierry Loiseau ; Dermot O'Hare ; and Gé ; rard Fé ; rey
- 刊名：Chemistry of Materials
- 出版年：2002
- 出版时间：October 2002
- 年：2002
- 卷：14
- 期：10
- 页码：4448 - 4459
- 全文大小：350K
- 年卷期：v.14,no.10(October 2002)
- ISSN：1520-5002
文摘
Two one-dimensional gallium fluorodiphosphates Ga(P2O7)F·H3N(CH2)3NH3·3H2O, 1, andGa(P2O7)F·H3N(CH2)3NH3·H2O, 2, have been synthesized under mild conditions (<100 
C)from aqueous mixtures of Ga(NO3)3·6H2O, P2O5, 1,3-diaminopropane, and HF. Theirstructures consist of anionic chains of formula Ga(P2O7)F2- containing corner-sharing{GaO4F2} octahedra linked together via fluorine and P2O7 units, which are charge-balancedby propyldiammonium dications. During the hydrothermal synthesis of the open-frameworkthree-dimensional ULM-3, compound 2 has been identified as the crystalline intermediatephase when phosphorus pentoxide is used as a starting material. This process has beenfollowed in situ with time-resolved energy-dispersive X-ray diffraction (EDXRD), whichreveals that dissolution of the one-dimensional phase 2 occurs before the rapid crystallizationof ULM-3. If compound 2 is quenched from hydrothermal conditions, rapid and reversibleconversion to compound 1 takes place. The two chain phases are thus solid precursors ofthe microporous ULM-3, and tracking the transformation process using in situ EXDRD showsthat dissolution of 1 takes place before crystallization of 2 and then further transformationinto the 3D phase, with the 1 and 2 acting as reservoirs of reactive species for ULM-3crystallization.
C)from aqueous mixtures of Ga(NO3)3·6H2O, P2O5, 1,3-diaminopropane, and HF. Theirstructures consist of anionic chains of formula Ga(P2O7)F2- containing corner-sharing{GaO4F2} octahedra linked together via fluorine and P2O7 units, which are charge-balancedby propyldiammonium dications. During the hydrothermal synthesis of the open-frameworkthree-dimensional ULM-3, compound 2 has been identified as the crystalline intermediatephase when phosphorus pentoxide is used as a starting material. This process has beenfollowed in situ with time-resolved energy-dispersive X-ray diffraction (EDXRD), whichreveals that dissolution of the one-dimensional phase 2 occurs before the rapid crystallizationof ULM-3. If compound 2 is quenched from hydrothermal conditions, rapid and reversibleconversion to compound 1 takes place. The two chain phases are thus solid precursors ofthe microporous ULM-3, and tracking the transformation process using in situ EXDRD showsthat dissolution of 1 takes place before crystallization of 2 and then further transformationinto the 3D phase, with the 1 and 2 acting as reservoirs of reactive species for ULM-3crystallization.