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http://ir.lib.ncu.edu.tw/handle/987654321/6255
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| 題名: | 釹/鐠草酸甲基磷酸鹽之合成、結構鑑定與性質研究;Synthesis , Crystal Structures and Properties of Lanthanide Oxalatophosphonates : Na[Ln3(H2O)4(C2O4)4(CH3PO3)]·2H2O (Ln = Nd and Pr) |
| 作者: | 黃雅玲;Ya-ling Huang |
| 貢獻者: | 化學研究所 |
| 關鍵詞: | 鑭系草酸甲基磷酸;水熱合成;hydrothermal;Lanthanide Oxalatophosphonates |
| 日期: | 2007-06-28 |
| 上傳時間: | 2009-09-22 10:16:29 (UTC+8) |
| 出版者: | 國立中央大學圖書館 |
| 摘要: | 本論文研究利用中溫水熱法合成新穎鑭系金屬草酸甲基磷酸鹽 化合物：Na[Ln3(H2O)4(C2O4)4(CH3PO3)]·2H2O [Ln = Nd (A) and Pr (B)]。藉由一系列鑑定方法，包括以Ｘ光單晶繞射法決定出化合物 的結構與化學式，再搭配元素分析、紅外線光譜、粉末繞射、熱重 分析及超導量子干涉等方法進行結構組成分析、熱穩定性、熱分解 反應及磁性等研究。並利用螢光光譜法深入探討放光譜線與單晶結 構之間的相關性。 化合物A和B 為等結構，所有的Ln 都是九配位。當中的Ln(1)O9 和Ln(2)O9 以邊共用及面共用的方式形成四聚體，此四聚體與草酸 和甲基磷酸連接形成單元層。而Ln(3)O9 則是與草酸形成Z 字型無 限延伸鏈，此單元鏈與單元層再經由草酸連結形成三維結構。 在磁性方面，化合物A 和B 皆為反鐵磁性，A 的μeff = 3.663 μb； B 的μeff = 3.795 μb，皆與其理論值接近。在放光光譜中，化合物A 的放光波段在近紅外光區，螢光生命期為1.6 ± 0.1 μs；化合物B 的 放光波段則涵蓋了綠光及紅光區，螢光生命期為1.7 ± 0.1 μs 和2.6 ± 0.1 μs。兩者之螢光生命期皆遠低於理論值，這是由於化合物當中含 水分子所造成的消激效應(Quenching Effect)。 A neodymium oxalatophosphonate and the praseodymium analogue, Na[Ln3(H2O)4(C2O4)4(CH3PO3)]·2H2O [Ln = Nd (A) and Pr (B)], have been synthesized by hydrothermal method and characterized by single-crystal X-ray diffraction and thermogravimetric analysis. We studied the photoluminescence spectra as well as the magnetic properties of the both compounds. The structure consists of layers built of tetramers of edge- and face-sharing LnO9 polyhedra connected by oxalate and methylphosphonate units, which are linked by zigzag infinite chains of oxalate-bridged LnO9 polyhedra to form a 3-D framework. They are the first examples of lanthanide oxalate-methylphosphonate. The μeff of Nd is 3.663 μb and the μeff of Pr is 3.795 μb; both are very close to the theoretical values. The Nd compound displays characteristic emission bands in the near IR region with lifetime 1.6 ± 0.1 μs. Luminescence of the Pr compound consists of many emission bands at 480-760 nm with lifetime 1.7 ± 0.1 μs and 2.6 ± 0.1 μs, respectively. The lifetimes of both compounds are much shorter than the expected values due to the quenching effects of water molecules in the structure. Crystal data for the Nd compound follow: triclinic, P`1 (No. 2), a = 9.0682(2) Å, b = 9.5114(3) Å, c = 14.0066(4) Å, a = 74.975(2)°, b = 86.534(2)º, g = 82.725(2)°, and Z = 2. Crystal data for the Pr compound are the same as those for the Nd compound except a = 9.125(1) Å, b = 9.549(1) Å, c = 14.073(2) Å, a = 75.086(2)°, b = 86.611(2)º, and g = 82.545(2)°. |
| 顯示於類別: | [化學研究所] 博碩士論文
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