矽酸與磷酸鈾之合成、晶體結構與性質研究; Synthesis,Crystal Structures and Properties of a Uranium Silicate and a Uranium Phosphate

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/60570

Title:	矽酸與磷酸鈾之合成、晶體結構與性質研究;Synthesis,Crystal Structures and Properties of a Uranium Silicate and a Uranium Phosphate
Authors:	張育誌;Chang,Yu-chih
Contributors:	化學學系
Keywords:	矽酸;磷酸;鈾;水熱法;晶體合成;晶體結構;silicate;phosphate;uranium;hydrothermal synthesis;crystal;structure data
Date:	2013-07-15
Issue Date:	2013-08-22 11:40:54 (UTC+8)
Publisher:	國立中央大學
Abstract:	本論文利用高溫高壓水熱法合成一個新的鈾矽酸鹽[Na9F2][(UVO2)(UVIO2)2(Si2O7)2] (A1)及一個鈾磷酸鹽化合物Na10UIV2(PO4)6 (A2)。藉由單晶X 光繞射方法鑑定出化合物的晶體結構，以粉末X 光繞射分析儀確定樣品純度以利後續分析，再以X 光能量散佈分析、電子探測微分析和X 光光電子光譜等方式進行定性與定量之分析。A1 結構為一新穎的五、六混價鈾矽酸鹽，結構中罕見的包含一條利用Na+ 和F- 鍵結之無限延伸的鏈狀結構。結構中的矽酸鹽形成一個 [Si2O7]的Sorosilicate 並且和UO6 利用共角的方式形成二維的層狀結構。此化合物為第一個利用高溫高壓水熱法成功合成的Salt-inclusion 結構，同時也是第一個混價的salt-inclusion 結構。A2 為一新穎的磷酸鈾結構，具有一個連體十二面體的UO8 單元，利用共角或共邊的方式和單一的磷酸鹽進行連結，因此形成一個三維的開放式骨架。結構中具有12 員環孔道，而所有10 個陽離子都座落在孔道當中。此化合物為第一個利用高溫高壓水熱法合成得到的新鈾磷酸鹽。 A salt-inclusion mixed-valence uranium(V,VI) silicate,[Na9F2][(UVO2)(UVIO2)2(Si2O7)2](A1), and a uranium(IV) phosphate,Na10UIV2(PO4)6 (A2), was synthesized under hydrothermal condition at 585oCand 160MPa, and structurally characterized by powder and single X-raydiffraction. These compounds were further characterized by EDX, EPMA, XPS and SHG.Compound A1 is a novel uranium(V,VI) silicate. The structure caotains 2D sheet of uranyl sorosilicate with the composition [UO2Si2O7] which connected by U(1)VO6etragonal bipyramids to form thick layers. The Na+ cations are located at sites in the intralayer and interlayer regions. In adition to Na+ cations,the interlayer region also contains F- anions such that infinite chains with theformula FNa1/1Na4/2 are formed. The compound A1 is not only the first example of salt-inclusion metal silicate synthesized under high-temperature,high-pressure hydrothermal onditions, the first salt-inclusion mixed-valence uranium silicate, but also the first mixed-valence uranium(V,VI) silicate in the literature.Compound A2 is a new tetravalent uranium phosphates. The valence state of uranium was established by U 4f X-ray photoelectron spectroscopy. The structure contains UO8 snub-disphenoidal polyhedral which are linked to monophosphate tetrahedral bt vertex- and edge-sharing such that a 3D framework with 12-sided circular and rectangular channels is fromed. All ten sodium sites are situated inside the channels and are fully occupied. These are the first uranium(IV) phosphate synthesized under high-temperature, high-pressure hydrothermal condition.
Appears in Collections:	[Graduate Institute of Chemistry] Electronic Thesis & Dissertation

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