鈾鍺酸鹽之合成與結構鑑定

Synthesis and Structural Characterization of Uranium Germanates

陳俊良(Chun-liang Chen)

指導教授 ： 李光華

國立中央大學/理學院/化學系/碩士(2012年)

摘要

本論文以高溫高壓水熱法合成三個鈾鍺酸鹽化合物Rb10(UO2)4Ge11O29(OH,F)4 (A1)、Rb3UGe7O18 (A2)以及Cs3.18(U3O3)(Ge2O7)2 (A3)。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供後續分析，例如：紅外光譜圖分析、X光能量散布分析、電子探測顯微分析以及電子能譜分析等。
A1為一個新穎的六價鈾鍺酸鹽，結構中的鍺氧四面體皆以共角的方式連接形成具有十二員環的孔道，再與鈾氧雙四角錐共角連接形成的三維結構，此結構中，在b軸方向存在著以鍺氧四面體及鈾氧雙四角錐所形成的四員環、五員環、七員環以及八員環孔道。
A2為結構中少見同時存在鍺氧四面體與鍺氧八面體，每個鍺氧六面體與六個共角連接形成三員環的Ge3O96- 相連在ab平面上形成鍺酸鹽三層結構，每個層包含九員環孔道，每個三層再與鈾氧八面體連接，形成三維的結構。並將此化合物與文獻中少見的五價鈾化合物做比較。A3結構中存在－UV－O－UIV/V－O－UIV/V－O－UV－的無限鈾氧鏈，每條鈾氧鏈與Ge2O7以共角方式相連形成三維骨架。

關鍵字

鈾 ； 鍺酸鹽 ； 水熱法

並列摘要

We have used high-temperature , high-pressure hydrothermal method to synthesize three uranium germanates, Rb10(UO2)4Ge11O29(OH,F)4 (A1), Rb3UGe7O18 (A2) and Cs3.18(U3O3)(Ge2O7)2 (A3). The crystal structures were determined by single-crystal X-ray diffraction. The purity of each compound was confirmed by powder X-ray diffraction. These compounds were further characterized by IR, EDX, EPMA and XPS.
A1 is a new uranium (VI) germanate. GeO4 tetrahedra are connected by sharing corners to form twelve-membered rings. Adjacent germanate chains are connected by UO6 tetragonal bipyramid to form three-dimension framework with four-ring, five-ring, seven-ring and eight-ring channels along b-axis.
A2 is a pentavalent uranium germanate , each [6]GeO6 octahedron is bonded to six three-membered single-ring [4]Ge3O96− units to form germanate triple layers in the ab plane. Each layer contains nine-ring windows. The triple layers are further connected by UO6 octahedra to form a three dimensional framework.

並列關鍵字

hydrothermal synthesis ； Uranium ； germanate

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