合成一系列新的碳軸側臂雙苯十九環冠醚,用以探討對鹼金屬離子之錯合現象及形式,利用13C-NMR金屬誘導變化效應輔以1H-NMR光譜變化,可看出冠醚與金屬離子錯合時構形的改變情形,十九環碳軸冠醚與鉀離子及銀離子形成1:1錯合,而且橋頭碳上的氧原子在錯合過程中具重要地位。 引入不同發光團側臂可以快速地以螢光光譜在定性上測得金屬離子對冠醚螢光訊號強弱的影響:鹼金屬離子使螢光強度增強,銀離子使螢光強度減弱;並可測知冠醚與金屬的錯合能力大小,測得對K+有最大的錯合穩定常數。 利用快速原子撞擊質譜法迅速地測知冠醚與金屬離子錯合的形式與能力,亦可看出十九環碳軸冠醚與鉀離子及銀離子形成1:1錯合。 利用十九環冠醚對鉀離子的選擇性,應用於選擇性薄膜電極的材料。實驗結果顯示,以冠醚3c-PVC-NaTPB -NPOE和冠醚3d-PVC-NaTPB-NPOE製成鉀離子選擇薄膜電極,分別得到55.38和53.27mV/decade接近於能士特斜率,這兩支電極對鉀離子的選擇性皆比對其它鹼金、鹼土族金屬離子為佳。
A new series of sym-dibenzo-19-crown-6 ethers with different sidearms have been synthesized . 13C and 1H NMR spectroscopies were used to investigate the complex formation between these lariat crown ethers with alkali metal cations. Results showed that these C-pivot sidearm lariat crown ethers form 1:1 complexes with K+ and Ag+ ions. In addition, the oxygen atom on the top of the bridged carbon chain plays an important role in the complexing formation. Crown ether-linked different fluorophores are well suited to the recognition of traces of metal ions. The addition of K+ enhanced the fluorescence emission intensity while the addition of Ag+ quenched the fluorescence intensity. In addition, their complex abilities were determined by the fluorescence studies. Fast-atom-bombardment (FAB) mass spectrometry was used as a fast scanning method to study the of stoichrometry of the complexes. It is also shown that sym-dibenzo-19-crown-6 derivatives form 1:1 complexes with K+ and Ag+ ions. Poly(vinyl chloride) (PVC) membrane electrodes based on sym-dibenzo-19-crown-6 carriers were prepared and tested for selective detection of potassium ions. The best performance observed include the two membrane electrode with the following composition: (1) 3c-PVC-NaTPB-NPOE and (2) 3d-PVC-NaTPB-NPOE. These two membrane electrodes show Nernstain response toward K+ at 55.38 and 53.27 mV per decade, respectively. The electrodes revealed good selectivities with respect to the other alkali metal ions、alkaline earth metal ions .