利用簡單的Williamson醚類合成法，合成一系列新的不同碳
軸側臂的對稱雙苯十六-冠-5醚，用以探討系列對金屬離子之錯
合現象，以找出對銀離子有最佳選擇性的系統。首先，利用快
速原子撞擊質譜法，來篩選此系列索套型冠醚對那些金屬離子
有較佳的錯合能力。
由於13C-NMR光譜中金屬誘導變化效應，可看出冠醚對金
屬離子錯合時構型的改變。如果側臂或主環上的異原子參與配
位，則其電子密度會減少，而使得鄰近之碳原子13C-核磁共振
光譜線產生位移。另外一種會使由已解出的13C-核磁共振光譜線
產生位移的原因是曲於配位而使環上之碳碳鍵或側臂構型改
變。由已解出的Sodium(hydroxy-sy-dibenzo-16-crown-5 ether)
bromide及Lead(Ⅱ)(2’-methoxyethyl-sym-dibenzo-l6-crown-5
ether)nitrate X光單晶繞射結果，與作13C-NMR的金屬誘導變化做
比較，發現二者的結論都相同都是參與配位時有最大的化學位
移變化。因此，可從光譜中之誘導變化及其效應發現冠醚錯合
前後的變化，進而推導出索套型冠醚與金屬離子間的錯合方
式。
使用真實溶液的萃取的目的是確定金屬離子可被萃取進入
含這些索套型冠醚之有機層以確定這些索套型冠醚的萃取能力
與選擇性。最後，以液膜離子傳輸實驗研究此類索套型冠醚對
金屬離子的傳輸能力。
從結果得知金屬離子由引入的側臂配位基與冠醚的氧原子
共同配位，可以有效地抓住金屬離子，因而提升索套型冠醚的
配位能力。此類索套型冠醚與銀離于形成1：1錯合，其中以具
有3’-丁烯基之對稱雙苯16-冠-5 醚對銀離子具有最佳的選擇性。

A new series of sym-dibenzo-16-crown-5 ethers with different sidearm have been synthesized by simple Williamson ether synthesis. The aim of this thesis is to find those lariat crown ethers, which are selectively bind with silver ion. FAB-MS has been used as s fast scanning method to choose metal ion which will complex with lariat crown ethers.
Metal-induced change in 13C chemical shift are observed due to conformational rearrangement, and/or reduction of electron density of the heteroatoms following complex formation. The predominant change in13C chemical shift(Δδ) are observed in those carbon atoms which participated in the three dimensional ligation of metal ions. Two single crystals of the metal-lariat crown ether complexes have been obtained and analyzed by X-ray diffraction： Sodium (hydroxy-sym-dibenzo-16- crown-5 ether) bromide and Lead(Ⅱ) (2’-methoxyethyl-sym-dibenzo-16- crown-5 ether ) nitrate. By comparison of the X-ray diffraction data with that obtained from 13C-nmr; the conclusions are parallel to each other. It is shown that the introduction of the sidearm enhance of the complexation of crown ethers with metal ion.
Solvent extraction is used to find out which lariat crown ethers can extract Ag+ Pb2+ and Na+ ions into organic solvent. Liquid membrane transport experiments are also carried out to find out their transport abilities.
Results shown C-pivot sidearm lariat crown ethers form 1 : 1 complexes with Ag+ ion. Among them, 3-butenyl sym-dibenzo-16- crown-5 ether gives the best Ag+ selectivity.