| 摘要: | 本實驗系列一主要設計並合成以N, N’ –Bis [1-(3’,4’–di (alkoxy) phenyl) -3-oxopropenyl]-1, 2-diaminopropane 結構為主的配位基，再分別以 Cu (II), Pd (II) 及Ni (II) 金屬配位形成錯合物。本實驗設計在帶有四支長碳鏈及連接基上不具有 OH 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 (n = 10, 12, 14, 16) 及 Pd (n = 10, 12, 14, 16)、Ni (n = 12, 16) 金屬錯合物，均具 Colh 相。在不同結構中這些液晶相的形成與性質，我們將會做進一步的探討與比較。 系列二為系列一配位基之類似結構。我們將固定其側鏈基碳數而改變中間橋接基的碳數。在帶有兩支側鏈基，其 n = 16，連接基碳數為m = 2~12之dimer中，其中間碳數具有層狀液晶相。具偶數碳為SmC (m = 4, 6, 8)；奇數碳為SmA (m = 5, 7)的奇偶效應產生。另一dimer系統為帶有四支側鏈基，其 n = 12，連接基碳數為m = 3, 4, 5, 6, 7, 9, 11, 12，但僅在短碳數 (m = 2, 3, 5) 有Colh相出現。在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。 此外，物性檢測方面會以 POM、DSC、XRD 等儀器做液晶相、熱性質及液晶分子排列的判定，並藉由 1H，13C-NMR 及 EA 等儀器鑑定化合物之結構及純度。 In this thesis two series of new mesogenic compounds were prepared and their mesomorphic properties studied. All organic comounds were characterized by 1H and 13C-NMR spectroscopy. The metal complexes were characterized by IR spectroscopy and elemental analysis. The mesomorphic behavior was investigated using polarized optical microscopy (POM), differential scanning calorimetry (DSC), and temperature dependent powder X-ray diffraction measurements (XRD). In series I, four Schiff bases derived from 1-(3,4-bis(alkoxy) phenyl)-3-hydroxyprop-2-en-1-ones (n = 10, 12, 14, 16) and their copper(II), nickel(II) and palladium(II) complexes were prepared. All the Schiff base ligands (n = 10, 12, 14, 16) exhibited hexagonal columnar phases (Colh). Palladium complexes (n = 10, 12, 14, 16) and Nickel complexes (n = 12, 16) complexes also columnar phases. However, all copper(II) were not mesogenic. The structures of mesophases were confirmed as hexagonal columnar phases (Colh) by powder XRD diffraction. X-ray single crystallographic analysis indicated the Pd center was coordinated as a square planar geometry and the Cu center was coordinated as a tetrahdral geometry. In series II, a total numbers of sixteen twin dimers with structures similar to those in series I were prepared and studied. The formation of mesophases were found to be dependent of alkoxy chain density and/or the carbon length in alkyl spacer (m). All twin derivatives with two terminal alkoxy chains (n = C16H31) exhibited layer smectic phases and odd-even effect was also observed. All derivatives with an even-carbon spacer (m = 4, 6, 8, 10) formed SmC phases and other derivatives with odd-carbon spacer (m = 5,7) exhibited SmA (m = 5, 7). However, all dimers derivatives with four alkoxy sidechains (n = 12) and shorter spacers (m = 3, 5) exhibited hexagonal columnar phase. |
