The Studies in the Calix[4]arenegrafted silica gel

• Main Authors: Liao Ya-loung, 廖亞龍
• Other Authors: 林 立 錦
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/73056021823662261583

碩士 === 中國文化大學 === 應用化學研究所 === 93 === 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, calix[4]arene grafted silica gel, was proposed 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 reverse Friedel-Crafts reaction to give parent calix[4]arene. Calix[4]arene was grafted onto silica gel by 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 afford a p-nitrobenzoate moiety. The nitro group was then reduced with aqueous sodium dithionite, and the diazotization of the resulting aniline moieties following with diazo-coupling reaction with calix[4]arene gave a deep red calix[4]arene grafted silica gel. TGA analysis indicated that 26％(w/w) of calix[4]arene grafted silica gel was organic portion, which is equivalented to 4.36*10-4 mole of calix[4]arene per gram of grafted silica gel. The bonding ability toward magnesium was shown to be better than the original silica gel in basic conditions. The synthetic procedure, the results of TGA analysis and the results of AA analysis were discussed.