人工合成的羧基雙苯16冠5及羥基雙苯16冠5對鈉離子均有很好的選擇性，
當鈉離子的相對陰離子（counter anion） 具有較佳的酯溶性或水溶液較
偏向鹼性時，鈉離子的輸送會明顯升高。而鈉離子的水合離子較不穩定
者, 亦會得到較佳的輸送效果。當羧基雙苯16冠5對鉀鹽及鈉鹽進行輸送
，不論是競爭輸送或是雙向輸送，顯示出其對鈉離子的優越的選擇性，但
不論是競爭輸送或雙向輸送，都顯示出被輸送到接受層的鈉離子濃度約僅
有單一鈉鹽輸送時的70%-80% 左右。 翼式官能基在本研究中顯示不僅會
加快鈉離子的輸送，同時亦會影響冠狀醚孔洞的大小，具羧基的冠狀醚有
類似手臂的功能，能幫助抓緊金屬離子，使冠狀醚和金屬離子之間的錯合
效果更好，同時羧基亦有利於以離子交換方式輸送機構的進行。本研究中
使用的冠狀醚羧基雙苯16冠5無法應用在克萊森縮合反應中做為相轉移催
化劑，因其所具有的羧基pKa 值遠較a-氫（a-hydrogen）為小，然而冠狀
醚羥基雙苯16冠5就可勝任愉快。由於冠狀醚羥基雙苯16冠5 與單苯15冠5
，雙苯18冠6等比起來，有較接近鈉離子大小的孔洞，故對催化的效果最
佳，達到70%以上。溶劑效應方面，介電常數較低的溶劑較不易和被活化
的陰離子溶合，亦即較不會干擾烯醇根陰離子的形成，而使產率較佳。在
溫度效應研究中，雖然溫度升高對鈉鹽在苯的溶解度提高，但高溫對冠狀
醚和金屬的錯合造成破壞，故不高不低的溫度（40oC）反而較利反應進行
。在冠狀醚及反應物濃度研究，冠狀醚及反應物的濃度比為 1/1時，可得
到較經濟又符合高產率的結果。

The carboxylate crown ethers (sym-hydroxydibenzo-16- crown-5,
DB16C5OH and sym-dibenzo-16-crown-5-oxyacetic acid, DB16C5COOH)
were synthesized to apply as ion transport carriers and play as
phase transfer catalyst (PTC) in organic synthesis. In the
study of Na+ ion transport with sym-DB16C5COOH ,it seems to
indicate that the bigger counter anion and more hydrophobic
anions of sodium salts exhibited better transport.Besides the
solvation of the salts, the pH values of source solution and
target solution showed some effect on Na+ ion transport. In
addition ,crown ethers effect on the Na+ ion transport was
investigated ,the Na+ ion transport ability of various crown
ethers seems to decrease in the order : DB16C5COOH>B15C5COOH>
DB16C5OH>B15C5,it shows that side chain functional group on
crown ethers may influence the Na+ ion transport ability. Crown
ethers were applied as phase transfer catalyst (PTC) in the
Claisen condensation reaction between ethyl acetate and ethyl
benzoate.It showed that DB16C5OH was quite a good catalyst in
the reaction which can increase the yield of the product from
10% to 70% for only 6 hours. The effects of crown ethers on the
yield of the product were in the order: DB16C5OH > B15C5 > DB18
C6 >Blank>DB16C5COOH. Effect of solvent and temperature on the
catalytic Claisen condensation reaction were also investigated.
The reaction in lower polar solvents seems to show higher
yield . The temperature study on the catalytic reaction reveals
that it has a optimum temperature at 40oC and with the order
40oC > 60oC > 25oC . This maybe attributed to high solubility
of NaOEt, but less stability of Na+/crown ether complexes at
higher temperature . Concentration effect of crown ethers and
reactant were also studied and discussed. The best result was
obtained with the ratio crown ether/ reactants = 1/1.
The carboxylate crown ethers (sym-hydroxydibenzo-16- crown-5,