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| 題名: | 含2-氨基-5-硫基-1,3,4-噻二唑之金屬配位聚合物之合成、結構解析及介電性質研究;Synthesis, Structural Characterization and Dielectric Properties of Metal Complexes with 2-Amino-5- mercapto-1,3,4-thiadiazole |
| 作者: | 高亞詮;Gao,Ya-chuan |
| 貢獻者: | 化學學系 |
| 關鍵詞: | 配魏化學;超分子化學;磁性;介電常數;Coordination Chemistry;Supramolecular Chemistry;Magnetic;Dielectric |
| 日期: | 2014-06-30 |
| 上傳時間: | 2014-08-11 18:14:09 (UTC+8) |
| 出版者: | 國立中央大學 |
| 摘要: | 本文使用過渡金屬離子和2-amino-5-mercapto-1,3,4-thiadiazole (Hamtd) 經由自組裝的方式合成出{[Ni4(amtd)6(H2O)6(OH)2]‧(CH3OH)(H2O) (1), {[Ni4(amtd)6(H2O)6(OH)2]‧(H2O)2 (2), 5,5′-disulfanediylbis(1,3,4-thiadiazol-2-amine) (3)、{[Ni4(amtd)6(azpy)(OH)2(H2O)3(CH3OH)]‧(CH3OH)n (4), [Co(amtd)2]n (5)、[Mn2(amtd)4]n (6)等六個化合物，並進一步探討其晶體結構特性、熱穩定性及介電等物性的鑑定分析。
鎳金屬離子和Hamtd配子於甲醇、水的混合溶劑中，以室溫靜置的方式可同時得到化合物1、2。相同條件下若將反應物濃度降低可得純化合物1。而利用水浴80 °C的條件下可生成純化合物2。化合物1、2具有相似的固態結構，是以六配位金屬中心形成四核金屬簇的單分子結構，單分子間藉由氫鍵作用力與π−π 作用力形成三維的超分子架構。於純化合物2之製備條件下，若加入4,4′-azopyridine ，溶液之pH值為6~7之間，發現Hamtd配子耦合成具有S−S單鍵之雙硫有機化合物3。有趣的是，若將原本可形成化合物3的溶液酸鹼值調為9~10之間，則得到化合物4，結構解析顯示4,4′-azopyridine將四核鎳的金屬簇連接成一維結構。化合物5、6的金屬中心分別為Co與Mn，是以六配位的金屬中心所形成的一維結構。
在磁性方面，化合物1、化合物2之直流磁化率χMT數據顯示，兩者為反鐵磁性。化合物5金屬中心為鈷，磁性量測顯示為順磁性，化合物6之中心金屬為錳，為鐵磁性材料。
在介電性質的量測方面，化合物1、2由於含有高極性的溶劑水與甲醇，故所量測到的κ值大約在8~9，屬於high-κ材料。化合物5、6結構中，沒有極性客分子的存在，所量測到的數值大約在2.4~2.6，是屬於low-κ的材料。
;In this thesis, a series of supramolecular compounds and coordination polymers were synthesized via self-assembly processes and their structures and properties were examined.
Compounds {[Ni4(amtd)6(H2O)6(OH)2]‧(CH3OH)(H2O)} (1), and {[Ni4(amtd)6(H2O)6(OH)2]‧(H2O)2} (2) were simultaneously obtained by the reaction of nickel salts with 2-amino-5-mercapto-1,3,4-thiadiazole (Hamtd) ligand in a mixture of H2O/MeOH at room temperature. Under similar reaction conditions, pure compound 1 was obtained when the concentration of the solution was decreased. Interestingly, pure compound 2 was the only product produced at 80 °C under the same conditions. The reaction of Ni2+ with Hamtd in a H2O/MeOH solution in the presence of 4,4′-azopyridine (azpy) ligand at 50 °C, while maintaining the pH at 6−7, resulted in the generation of the disulfide compound 5,5′-disulfanediylbis(1,3,4-thiadiazol-2-amine) (3). By adjusting the pH value of the above solution to 9−10, compound {[Ni4(amtd)6(azpy)(OH)2(H2O)3 (CH3OH)]‧(CH3OH)2}n (4) was produced. Treatment of Co2+ and Hamtd in H2O at 140 °C afforded a ID coordination polymer [Co(amtd)2]n (5). The reaction of Mn2+ with Hamtd in a mixture of H2O/MeOH at 50 °C resulted in the formation of [Mn2(amtd)4]n (6). Compounds 1−6 were characterized by infrared spectroscopy (FT-IR), powder X-ray diffraction, (PXRD), elemental analysis (EA), and thermogravimetric analysis (TGA). Their structures were further confirmed by single-crystal X-ray diffraction analysis.
The dielectric properties of compounds 1, 2, 5 and 6 were investigated. The results of dielectric measurement of compounds 1 and 2 revealed a κ value of 8.59 for 1 and 10.09 for 2 at 1 MHz. The high dielectric constant of these compounds can be attributed to the presence of polar guest molecules. On the contrary, the dielectric values for compounds 5 and 6 were found to be 2.42 for 5 and 2.57 for 6 at 1 MHz. These low κ values are due to the absence of polar guest molecules. This fundamental study encouraged us to prepare low dielectric materials from simple and low cost starting materials via self-assembly processes. |
| 顯示於類別: | [化學研究所] 博碩士論文
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