摘要: | 本論文系列一合成設計出含有benzoxazole衍生物的配位基和金屬錯合物 (鈀、銅、鋅),藉由改變側鏈基的長短,討論其液晶之行為,並透過DSC、POM、XRD等儀器來觀察其液晶在不同溫度下的性質。研究發現,含有benzoxazole衍生物的配位基當其側鏈基長碳鏈數目為10和12時具有SmA液晶相,且由於此配位基屬於雜環類分子,具有donor-acceptor interaction,因此具有發光的性質,所以進一步利用UV-vis absorption與PL來研究其光學性質。鈀的金屬錯合物側鏈基長碳鏈數目為10,12和14時,具有SmC液晶相,而所有銅和鋅的金屬錯合物皆不具任何液晶相。 系列二合成出具有cis-Enaminoketones結構之配位基和金屬錯合物 (鈀、鎳),本實驗設計在帶有四支長碳鏈及改變其連接基上官能基的情況下,觀察是否有液晶相形成,經 POM 及 XRD 鑑定後,發現配位基及 Pd、Ni 金屬錯合物部分具有Colh 相。在不同結構中這些液晶相的形成與性質,我們做了進一步的探討與比較。接著我們將固定其側鏈基碳數而改變中間橋接基的碳數。dimer系統為帶有四支側鏈基,其 n = 14,連接基碳數為m = 2, 3, 4, 5, 6, 7, 8, 9,但僅在碳數 (m = 2, 3, 5, 7) Colh相出現。此外,可以發現連接基碳數中有奇數碳澄清點較低偶數碳澄清點較高的奇偶效應產生。 In series I the synthesis, characterization and mesomorphic behavior of a series of benzoxazole derivatives 2 and their complexes 1 (M = Pd, Cu, Zn) are described. The mesomorphic properties were investigated using polarized optical microscopy (POM), differential scanning calorimetry (DSC), powder X-ray diffraction (XRD). The results indicated that ligands based on benzoxazole with carbon length of n = 10, 12 showed smectic A (SmA) mesophase. All copper (II) and zinc (II) complexes were not mesogenic. However, palladium (II) comlexes with carbon length of n = 10, 12, 14 showed hexagonal columnar mesophase (Colh). The difference in observed mesomorphic behavior might result from the geometry of central core. In series II, twin dimers and their palladium(II), and nickel(II) complexes were prepared. The formation of mesophases were found to be dependent of alkoxy chain density and/or the spacer. The mesophase was identified as hexagonal columnar (Colh) phase based on the optical texture and was also confirmed by powder XRD diffraction. |