| Summary: | 碩士 === 中國文化大學 === 應用化學研究所 === 94 === Calixarenes, which are cyclic oligomers of p-substituted phenols and formaldehyde, are able to include small organic molecules or metal ions within molecular cavities to from the “host-guest complexes”. This phenomenon has been proposed in the research area of micro-analysis detection devices, ion separation, and enzyme-mimic studies. The main purpose of this thesis is to develop a standard procedure for grafting the calix[4]arene onto silica gel. The grafted product was then subjected to serve as a stationary phase for the ion separation.
In the presence of a base, p-tert-butylphenol and formaldehyde was polymerized to form an yellowish precursor. Refluxing of this precursor in diphenyl ether for two hours yielded the p-tert-butylcalix[4]arene. The p-tert-butyl groups were then removed by AlCl3 catalyzed reverseFriedel-Crafts reaction to give parent calix[4]arene.
The calix[4]arene grafted silica gel was prepared in a four-step procedure. An 3-aminopropyl groups was introduced
by reacting triethoxy silane with silica gel, and the resulting aminopropyl silica gel (APSG) was further treated with p-nitrobenzoyl chloride to supply a p-nitrobenzoate moiety. The nitro group was then reduced by sodium dithionite, and the diazotization of the resulting aniline followed with diazo-coupling reaction with calix[4]arene gave the red calix[4]arene grafted silica gel.
The thermal gravimetric analysis (TGA) was applied to the products to determine the composition of the organic portion on grafted silica gel. The amount of the organic portion was in the range of 18.5% for the calix[4]arene grafted silica gel, which is equivalent to 3.02 mmole of calix[4]arene per gram of calix[4]arene grafted silica gel . The preliminary ionic extraction resulted for Cu+2 , Fe+2 , Pb+2 , and Cr+3 will also be discussed.
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