| 摘要: | 本論文研究旨趣為探討過渡金屬離子與手性配子L-thiazolidine-4-carboxylic acid (LTP)之自組裝反應，結構鑑定，與產物脫附水後之結構轉換。微調反應參數，如金屬離子與溶劑之種類，金屬離子與配子之濃度可成功合成出3系列6個手性金屬化合物。
第一系列錯化物中，化合物 [M(LTP)2(H2O)2] (1, M = Zn
2, M = Co
3, M = Ni)均為單核化合物，且互為isomorphous，中心金屬與LTP配子之氮原子和氧原子鍵結，及二個配位水形成八面體，單體間利用氫鍵作用力形成三維的超分子。第二系列化合物 [Zn(LTP)2]n (4) 鋅金屬離子配位模式為二個LTP配基以3-(3 N, O2 : O2’)與一個LTP配基以1-(2 N, O2)的方式鍵結，形成五配位近似雙三角錐的幾何結構。且藉由LTP架橋向外延伸，形成一維鏈狀化合物。第三系列化合物 [M(LTP)2]n (5, M = Zn
6, M = Cd)的金屬離子分別為鋅和鎘，其中心金屬藉四個LTP配基以3-(3N, O2 : O2’)的模式鍵結形成八面體，並以LTP配基架橋形成4,4-membered ring，以此單元向外延伸形成二維格子狀結構，層與層間以ABAB方式排列堆疊。另外，化合物4及5為supramolecular isomer.
化合物16皆利用LTP配基架橋，連接金屬離子，形成零維、一維和二維結構。
本論文詳細探討實驗合成方法、結構組成、熱穩定性，並藉in-situ X光粉末繞射儀觀察金屬錯合物在不同溫度下的結構變化。此外，也仔細探討化合物1在高溫脫水後結構轉變成為化合物4、5的過程及路徑選擇。
This thesis focuses on the preparation of a series of metal complexes via the use of a combination of metal (Zn(II), Co(II), Ni(II), Cd(II) salts with a LTP (L-thiazolidine-4-carboxylate)) ligand under mild reaction conditions. Their structures were characterized by single-crystal X-ray diffraction analyses. The structures of the first series [M(LTP)2(H2O)2] (M = Zn(II) 1, Co(II) 2, Ni(II) 3) show that the metal ion is six-coordinated in a distorted octahedral geometry and bonded to two N and two O atoms from two LTP ligands with bis-chelating coordination mode and two water molecules. Hydrogen bonding interactions between the LTP ligand and the water molecule were observed to play an important role in the formation of their 3D hydrogen-bonded supramolecular architectures. The metal ion in the second series [M(LTP)2]n (M = Zn(II) 4) is five-coordinated, with a distorted trigonal bipyramidal geometry, bonded to two N and three O atoms from three LTP ligands. The metal ion in the third series of compounds [M(LTP)2]n (M = Zn(II) 5, Cd(II) 6) is six-coordinated in a distorted octahedral geometry, bonded to two N and four O atoms from four LTP ligands. In 4, one LTP ligand acts as a monodentate coordination mode through an O atom and the other two LTP ligands act as bis-chelating coordination modes through both N and O atoms with a metal ion to form a one-dimensional (1D) [Zn(LTP)2] chain. In 5 and 6, the two LTP ligands act as chelating agents through both N and O atoms and the other two LTP ligands are coordinated with metal ions via an O atom to form a two-dimensional (2D) wave-like network. These 2D layers are then arranged in an ABAB-type array via the intermolecular interactions of N-H×××S hydrogen bonds to form a 3D supramolecular architecture. The thermal stability of compounds 1-6 are studied by TGA analysis. In addition, in-situ PXRD measurements verify that the crystal engineering transformation of 1 to 4 and 1 to 5 in a major and minor product, respectively. |
