高溫高壓水熱法合成鋇硼酸鹽及其結構與性質研究;High-Temperature, High-Pressure Hydrothermal Synthesis, Structures and Properties of Barium Borates

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/76708

Title:	高溫高壓水熱法合成鋇硼酸鹽及其結構與性質研究;High-Temperature, High-Pressure Hydrothermal Synthesis, Structures and Properties of Barium Borates
Authors:	紀沛宏;Jih, Pei-Hung
Contributors:	化學學系
Keywords:	水熱合成;非線性光學
Date:	2018-07-30
Issue Date:	2018-08-31 11:34:03 (UTC+8)
Publisher:	國立中央大學
Abstract:	本論文以高溫高壓水熱法合成兩個鋇硼酸鹽和一個鋇鎵硼酸鹽：Ba6B12O21(OH)6 (A1)、Ba4B11O18.7(OH)3.6.0.5H2O (A2)、Ba3Ga2[B3O6(OH)]2[B4O7(OH)2] (A3)。先由單晶X光繞射儀，解析出化合物的晶體結構，再以實測粉末X光繞射圖與理論計算X光繞射圖比對，確定樣品為純相後再進行二次倍頻強度(SHG)量測、紅外光譜儀(FT-IR)進行分析，並以價鍵和理論計算出化合物中各原子價數作為參考。化合物A1為P32非中心對稱空間群的透明無色柱狀晶體，結構中的BO3平面三角形及BO4四面體以共用氧原子的共角方式連接形成[B4O7(OH)2]，進而無限延伸成一維單鏈，各單鏈之間再由鋇離子和氧的配位來穩定結構，而結構中的OH基也從FTIR得到驗證。化合物A2為P21/c中心對稱空間群的透明無色針柱狀晶體，為較複雜的層狀結構，每層有兩個由BO3平面三角形及BO4四面體所組成的單鏈，鏈和鏈之間又由[B5O12]∞所連接形成層，而結晶水就存在於結構中的層與層之間，而結構中的OH基也從FTIR光譜中得到驗證。化合物A3為Fdd2非中心對稱空間群的透明無色片狀晶體，為層狀結構化合物，每一層中由BO3平面三角形、BO4四面體及GaO4四面體組成上下兩個都具有九員環的2D無限延伸層[Ga2B6O12(OH)2]∞，且鋇離子就坐落於九員環中，中間再由[B4O7(OH)2]來連接形成層狀結構。其中A1經SHG量測後倍頻效率為SiO2的0.35倍並確認為非中心對稱空間群，A3也成功解決Ba3Ga2[B3O6(OH)]2[B4O7(OH)2] 中因為鋇離子分裂而造成R1值過高的問題。 ;Two barium borates, Ba6B12O21(OH)6 (A1) and Ba4B11O18.7(OH)3.6.0.5H2O (A2), and one barium gallium borate, Ba3Ga2[B3O6(OH)]2[B4O7(OH)2] (A3), were synthesized by the supercritical hydrothermal method and structurally chacterized by single-crystal X-ray diffraction and a combination of techniques such as infrared spectroscopy and second harmonic generation. Powder X-ray diffraction patterns were measured to confirm the purity of the samples for property and spectroscopy measurements, The structure of A1 contains 1-D borate chains built by the fundamental building unit [B4O7(OH)2]. Compound A2 contains [B5O12]∞ sheets which are linked by two types of borate chains to form a double-layer structure. Compound A3 has a double-layer structure containing two [Ga2B6O12(OH)2]∞ sheets linked by [B4O7(OH)2] groups. The compound was previously reported in the literature with unsatisfactory refinement results. The high-temperature, high-pressure hydrothermal method produced high quality crystals of A3 with considerably better refinement results. The presence of OH groups in these compounds were confirmed by infrared spectroscopy. A1 adopts a non-centrosymmetrric structure as indicated by second harmonic generation measurement results.
Appears in Collections:	[Graduate Institute of Chemistry] Electronic Thesis & Dissertation

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