| Abstract: | 本論文分為四個章節，第一章以鉑金屬為中心金屬連接兩個pyridyl pyrazolate 配位基形成雙聚物，此系列以代號Ptdax 表示，x 代表不同碳鏈長度。利用偏光顯微鏡、熱微差掃描分析儀及粉末X 光繞射確認此系列化合物均具有筒型液晶相，液晶溫度範圍大於250 oC 且其熱烈解溫度均高達340 oC。第二章仍以鉑金屬為中心金屬，連接兩個五炔苯基苯盤形單元。此系列以代號Pt1cx 及Pt1ocx 表示，cx 代表不同烷鏈碳鏈長度，ocx 代表不同烷氧鏈碳鏈長度。以系列化合物皆具有盤形向列型液晶相，具烷鏈鉑金屬雙聚物熱性質穩定。此外，化合物Pt1oc4 單晶繞射結果顯示具烷氧鏈鉑金屬雙聚物整體分子平面性較好，因此粉末X 光繞射得到此類分子具有較大範圍排列的結果。第三章中分子設計以一個多炔苯基苯為主體，分別接上不同數量的炔吡啶基。利用推拉電子基效應使分子中具有拉電子基的官能基其電子密度分部落在前鋒軌域理論的LUMO，而具有推電子基的官能基其電子密度分部落在前鋒軌域理論的HOMO，利用此分子設計的差異在不同酸性、不同金屬及溶劑條件下研究液晶及光學性質。此系列以代號1N1,x、2N1,x、3N1,x 及3N2,x 表示，x代表不同碳鏈長度。結果顯示此系列化合物隨著碳鏈及炔吡啶數目不同而產生盤形向列型或筒型液晶相。此外，利用偏光顯微鏡及粉末X 光繞射結果證實化合物1N1,12 具有熱致型及溶致型液晶性質；此化合物溶於四氫伏喃(THF)溶劑中後再加入W6+及Pd2+金屬，造成強消光現象且Pd2+金屬還造成20 nm 的紅位移，證實化合物1N1,12 對此兩金屬有專一性。化合物1N1,12 及3N1,12 在2.0 當量的三氟乙酸中皆產生強消光現象，且兩化合物在具有相同當量的三氟乙酸中產生不同顏色，推測上述結果來自於分子設計造成不同的的電子密度分布而產生。第四章部分，利用日本慶應大學山田徹老師實驗室發展出的銀金屬催化系統利用添加二氧化碳進行環碳酸化反應而形成高純度旋光性化合物反應，在本實驗室發展出的五炔苯基苯盤形單元上進行Sonogashira 反應而形成具有室溫筒型液晶性質的化合物C2oc8。另一化合物EC2oc12 在圓二色光譜儀實驗中發現具有負型卡頓效應(Cotton effect)。
The thesis contains four chapters. In chapter one and two, we investigated the influence of the molecular packing of discotic platinated-metallomesogenic dimers on their mesogenic and optical properties, especially their photo-luminescent studies. In chater one, a platinum
chelated pyridyl pyrazolate ligands to form a square planar structure. The molecular design led the compounds possessed wide mesogenic temperature range (> 250°C) and achieved mesomorphically stable (Td > 340 °C). In chapter two, a spacer with platinum moiety bridged two discotic pentaynylethylbenzenes. The Pt1oc6 possessed wide nematogenic temperature range (> 130°C). Being compared with Pt1c4, the more planar structure of Pt1oc4 possessed longer molecular packing length found in the results of powder X-ray diffraction investigation. This indicated that the alkoxy chains potentially helps Pt1oc4 to achieve large
domain alignment. In chapter three, the molecular design concept based on adding donor and/or acceptor substituents to the chromophores at suitable positions resulted in separately electronic shifts in HOMO and LUMO into opposite directions. The discotic monopyridyl derivatives, 1N1,12 possessed both thermotropic and lyotropic properties. The 1N1,12 behaved as a enantiotropic liquid crystal and achieved room temperature Smactic C phase. Another tripyridyl derivative, 3N1,12 possessed columnar phase. The fluorescent investigation results showed
that 1N1,12 quenched almost all d8 metal ions and K+, Hg2+, Pd2+, V5+, and W6+. However, the 3N1,12 quenched only Cu2+, Hg2+, Pd2+, and W6+ metal ions. Besides, to titrate with tetrafluoric acid (TFA) from 0.5 to 2.0 equivalents, the emissive intensity decrease seriously. Both of the optical results indicated that the discotic-pyridyl derivatives could be tuned by the designed electronic distribution to bind individual metal ions and to manipulate the appeared colors in varied pH values. In the last chapter, a series of cyclic carbonated moiety attached on pentaphenylethylbenzene were synthesized. A room temperature (C2OC8) columnar mesogens were achieved. The CD investigatino of EC2OC12showed negative cotton effect. |
