| 摘要: | 本篇論文系列一合成設計出含有benzoxazole與benzothiazole衍生物的配位基和金屬錯合物(銅、鈀)，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8和10時具有N液晶相，側鏈基長碳鏈數目為12、14以及16時具有SmC液晶相；含有benzothiazole衍生物的配位基其側鏈基長碳鏈數目為8同時具有N液晶相以及SmC液晶相。將benzoxazole與benzothiazole衍生物的配位基和金屬配位，並藉由IR光譜確認配位基確實與金屬配位。POM發現benzoxazole衍生物之(銅、鈀)金屬錯合物皆不具任何液晶相。benzothiazole衍生物之銅金屬錯合物亦不具任何液晶相。benzothiazole衍生物之鈀金屬錯合物側鏈基長碳鏈數目為8, 10, 12, 14, 16時皆具有SmC液晶相。系列二合成設計出含有benzothiazole衍生物，置換苯環4位置上的取代基，探討取代基對液晶行為之影響，研究中發現末端若無任何取代基，則無法產生液晶性質；若末端取代基接上推電子基，則產生nematic液晶相；若末端取代基接上拉電子基，則產生SmA液晶相。並利用取代基常數、dipole moment等性質說明液晶相形成的原因。In the first series synthesis, characterization and mesomorphic behavior of a series of benzoxazole and benzothiazole derivatives 2 and their complexes 1 (M = Pd, Cu) 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 = 8, 10 showed nematic (N) mesophase; with carbon length of n = 12, 14, 16 showed smetic C (SmC) mesophase. All palladium (II) and copper (II) complexes of benzoxazole derivatives were not mesogenic. Ligands based on benzothiazole with carbon length of n = 8 showed nematic (N) and smetic C (SmC) mesophase; with carbon length of n = 10, 12, 14, 16 showed smetic C (SmC) mesophase. Copper (II) complexes of benzothiazole derivatives were not mesogenic. However, palladium (II) comlexes of benzothiazole derivatives with carbon length of n = 8, 10, 12, 14, 16 showed smetic C (SmC) mesophase.In the second series, the effect of substituent group on the formation of the mesophases were investigated by Hammett constant, and dipole moment. A SmA phase was observed for derivatives with a strong electrondrawing substituent, and a N phase was observed for the derivative with an electrondonating substituent. |
