| 摘要: | 第壹部分 :
於近期的文獻中，含BF2之錯合物與多雜環系統被廣泛的合成與討論，BF2 complex 因其特殊的光物理性質，在生物顯影、分子探針、發光材料、光感應器......等領域具有發展性，然而在液晶領域的例子為少數，因此本研究以Pyridine BF2 complex為研究核心，探討其液晶性質。
参考實驗室曾製備之化合物 I, II, III 及 IV，將其分子長度減半，使分子結構更加呈直線型，並增加 OH 官能基使分子極性增強，藉此探討 Pyridine 不同位相以及含硼錯合物對於液晶性質的影響，並觀察在不同側鏈基長短下對其液晶性質之影響。
成功以縮合反應合成出以 Pyridine 做為主要的 central core 之配位基 2a 及 2b，再與 boron difluoride (BF2) 形成錯合物 1a 及 1b；而經偏光顯微鏡及差示掃描量熱分析儀等儀器下證實，錯合物 1a 及 1b 皆為雙向型桿狀液晶SmA相。
與化合物 I, II, III 及 IV 對比，可發現液晶相範圍由原本的 29 C 大幅提升至53 C，證實了增加分子間氫鍵及趨於直線的結構有助於桿狀液晶的形成；除此之外，分子模擬之結果可推測桿狀液晶分子之排列及堆疊，經計算，模擬之分子長度大於X-粉末射線繞射儀實驗所得之分子長度，故可推定化合物 1a, 1b (n = 12) 由兩個分子組成一個桿，並排列成SmA相。
第貳部分 :
聚氨酯 (PU) 為一種聚合物，由於其結構排列、優異的拉伸強度和耐化學性而具有獨特的優勢。目前於聚氨酯 (PU) 聚合反應中，普遍使用含tin化合物作為催化劑 (i.e. DBTL)，然而有機錫具有日益嚴格的環保法規及環境劇毒，另尋其它無錫觸媒的催化劑以替代 DBTL 已成為另一必要趨勢。因此第二部分以金屬錯合物為研究主體，開發具有良好催化活性與選擇性的無毒或低毒性觸媒。
参考文獻，在 PU 催化反應中，具良好活性的金屬錯合物，將其更換中心金屬或對結構進行修飾，探討不同配位基或中心金屬對催化反應性與選擇性的差異。
;First Part :
Recently, five-circular heterocyclic ring and BF2 complexes have been widely discussed and synthesized. Because of the special photophysical properties of BF2 complexes, they have good potential in bioimagings, molecular probes, luminescent materials, light sensor, etc. However, liquid crystals are rarely used in these cases. Thus, this paper focuses on the liquid crystals’ properties of pyridine BF2 complexes.
Refer to Compound I, II, III , IV that prepared and studied in our labortatory, we decided to add an OH group and remove one of the alkoxy groups in order to get an asymmetric molecule. In addition, this molecule is tending to be straight, and the OH group can enhance its polarity. The effects of pyridine’s N-position and different numbers of alkoxy groups on the liquid crystals’ properties were also observed. All compounds were characterized by 1H and 13C-NMR spectroscopy, while their mesogenic phase properties were studied by polarized optical microscope (POM) and differential scanning calorimeter (DSC).
In contrast to compound I, II, III , IV , the temperature ranges of liquid crystals were highly increased, which met our expectation. Besides, for compound 1a and 1b, we could comfirm that two molecules were combined to form a rod through MM2 calculation, which arranged into SmA phase.
Second Part :
Polyurethane (PU) is a polymer with unique advantages due to its structural alignment, excellent tensile strength and chemical resistance. Recently, tin-containing compounds are commonly used as catalysts (i.e. DBTL) in polyurethane (PU) polymerization. However, organotin has increasingly strict environmental regulations and is highly toxic to the environment. Looking for other tin-free catalysts to replace DBTL has become necessary trend. Therefore, the second part study focuses on developing non-toxic or low-toxic metal complexes catalysts with catalytic activity and selectivity.
References, in the catalytic reaction of PU, the metal complexes show good catalytic activity. By Substituted central metal and modified structures, discuss the differences in catalytic reactivity and selectivity of different ligands or central metals. |
