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| 研究生： |
許文杰 |
|---|---|
| 論文名稱： |
以核磁共振光譜探討側臂冠醚與金屬離子在溶液中之錯合性質 NMR Spectroscopic Studies of the Complexing Behavior of Side-armed Crown Ethers and Metal Ions in Solution State |
| 指導教授： | 劉高家秀 |
| 學位類別： |
碩士 Master |
| 系所名稱： |
化學系 Department of Chemistry |
| 畢業學年度： | 82 |
| 語文別： | 中文 |
| 論文頁數： | 118 |
| 中文關鍵詞： | 核磁共振 、側臂冠醚 |
| 論文種類： | 學術論文 |
| 相關次數： | 點閱：152 下載：0 |
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金屬誘導變化可視為冠醚與金屬離子錯合時構形的重組，所以13C NMR可用來研究冠醚錯合前後構形的變化，並進而推測二者的錯合方式。
碳軸側臂冠醚與鈉離子形成1:1錯合，與鉀離子形成2:1三明治式（sandwich）錯合，與銀離子形成1:1錯合。而2-picolyl sym-dibenzo-16-crown-5 ether 則隨銀離子濃度不同而有不同的錯合方式。具酯基或氯取代基側臂冠醚則無法清楚表現與金屬離子之錯合方式。橋頭碳上之碳原子在錯合過程中具重要地位。
我們曾單離二個冠醚與金屬離子之單晶，並完成X-光單晶繞射研究，分別是無色的sodium(hydroxy-sym-dibenzo-16-crown-5 ether) bromide 晶體為餘方晶系（orthorhombic），空間群P212121 a=8.660(2), b=13.121(3), c=17.246(9)A, V=1960(1)A3,z=4,R=0.040,Rw=0.033，為一個七配位結構。藍色的[CuL2(H2O)2](ClO4)2(L=2-picolyl sym-dibenzo-16-crown-5 ether) 晶體為單斜晶系（monoclinic），空間群為C2/c，A=21.332(3)、b=14.218(7)、 c=36.21(2)A、 β=91.60(3)0，V=10978(8)A3，z=8，R=0.109，Rw=0.1060為一扭曲的八面結構。
Metal-induced changes are observed due to conformational rearrangements following complex formation. NMR spectroscopy has been applied to investigate complex. formation between crown ethers and metal ions. Conformations of the free and the complexed crown ethers have been studied using 13C NMR spectroscopy. The-strong influence of complexing on the chemical shifts of the single 13C NMR lines permits determination of the ligand-metal interactions.
C-pivot side-armed crown ethers form 1:1 complexes with Na+, 2:1 sandwich complexes with K+, and 1:1 complexes with Ag+. Morever, the complexing behavior of 2-picolyl sym-dibenzo-16-crown-5 ether varies significantly as concentrations of Ag+ changed. Yet, the complexing behavior of the ester-and chloro-side-armed crown ethers is less pronounced. The oxygen atom on the top of the bridged carbon chain plays an important role in the complexing process.
Two single crystals of the metal-crown ether complexes have been obtained and analyzed. Colorless crystal of sodium(hydroxy-sym-dibenzo-16-crown-5 ether) bromide crystallized in the orthorhombic space group P212121 with a=8.660(2), b=13.121(3), c=17.246(9)A, V=1960(1)A3,z=4,R=0.040,Rw=0.033. The molecule has a seven-coordinated structure. Blue crystal of [CuL2(H2O)2](ClO4)2(L=2-picolyl sym-dibenzo-16-crown-5 ether) crystallized in the monoclinic space group C2/c with a=21.332(3), b=14.218(7), c=36.21(2)A, β=91.60(3)°, V=10978(8)A(3), Z=8, R=0.109, Rw=0.106.
The molecule has a distorted octahedral structure.
