Kinetic study of the conformational conversion of syn- and anti- 1,3-diethoxycalix[4]diquinones

• Main Authors: CHEN PEI YU, 陳珮瑜
• Other Authors: Lee-Gin Lin
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/29192228401737388927

碩士 === 中國文化大學 === 應用化學研究所 === 97 === Calixarenes, which are cyclic oligomers of p-substituted phenols and formaldehyde, are able to include small organic molecules or metal ions within the molecular cavities to form ‘‘ host-guest ’’ complexes. These phenomena have been proposed in the applications of micro-analysis, ion separation, and enzyme-mimic studies. The main purpose of this thesis is to study the kinetic conversion rate between two conformational isomers of 1,3-diethoxycalix[4]diquinones。 In the presence of a base, p-tert-butylphenol and formaldehyde was polymerized, to form an yellowish precursor 26. Refluxing of this precursor in diphenyl ether yielded the p-tert-butylcalix[4]arene (1). The p-tert-butyl groups were then removed with AlCl3 by reverse Friedel-Crafts reaction to give the parent calix[4]arene (6). Literature reported that calix[4]arene was dialkylated by refluxing with alkyl halides and K2CO3 in CH3CN, and five different alkyl halides (iodoethane, 1-iodopropane, 1-iodobutane, benzyl bromide, and allyl bromide) were selected to give the corresponding syn-1,3-dialkoxy- calix[4]arenes 27-31. The chlorine dioxide oxidation of 1,3-diethoxy- calix[4]arene yielded two interconvertable conformational isomers of 1,3-diethoxycalix[4]diquinones (anti-32 and syn-33). It was observed that the interconversion rate between anti-32 and syn-33 was varied in different solvent system. Five solvent systems (CDCl3, CD3CN, acetone-d6 , benzene-d6 and DMSO-d6) was studied in this thesis, and the conversion rate constants of the anti-syn interconversion were measured.