• 作者： Wang, Maw-Ling; Yu, Chun-Chi
• 中文摘要： 本文主要利用相間轉移觸媒技術進行 2,4-dibromophenyl allyl ether合成及動力學之研究,為了獲得反應操作最佳條件,對於溶劑種類,反應物濃度,攪拌速率,觸媒種類及用量與溫度對allyl bromide轉化率之影響,皆做深入之測試。由實驗數據得知,當攪拌速率超過400rpm,其對反應轉化率之影響就不顯著了,使用溶劑之相對反應性為: dichloromethane>chlorobenzene>toluene。在反應中,如果使用大量之2,4-dibromophenol時,甚至使用chlorobenzene為溶劑,反應之轉化率可高達100%,在檢視所使用之相間轉移觸媒中,我們發現以Tetra-n-butyl ammonium bromide具有最佳之催化作用,所獲得之視反應速率(apparent reaction rate)與allyl bromide之量成線性關係,但是不與觸媒用量成線性關係。相對於反應物之用量,發現有一KOH用量之最佳值可獲得高產率之產物,本研究反應系統之活化能獲得為17.60kcal/g-mole。基於實驗數據,吾人發現本系統乃同時受制於反應動力學及質量傳送。
• 英文摘要： The allylation of 2,4-dibromophenol by phase transfer catalysis was studied. The effects of solvents, concentrations of reactants, agitation rate, catalysts and temperature on the conversion of allyl bromide were investigated in order to find the optimum operating conditions for this reaction. It is found that no agitation effect is observed when the agitation rate exceeds 400rpm. The order of the relative activities of the solvents is dichloromethane>chlorobenzene>toluene. Even in a chlorobenzene solvent, the conversion can be as high as 100% with respect to allyl bromide when 2,4- dibromophenol is in excess amount. Examination of the four kinds of quaternary ammonium salts revealed that tetra-n-butyl ammonium bromide will be the best phase transfer catalyst. The apparent reaction rate is of the first order on the quantity of allyl bromide but not on the quantity of the phase transfer catalyst. An appropriate amount of potassium hydroxide relative to the amount of the reactant is suggested in order to obtain a higher yield of the product. The corresponding activation energy of the apparent reaction rate constant is 17.60Kcal/g-mole. On the basis of the experimental data, the rate limiting steps include both the kinetics of the reaction and the mass transfer of the catalyst between two phases.
• 中文關鍵字： 相間轉移觸媒作用; 動力學; 合成; 2; 4-二溴酚丙烯化反應; 視反應速率
• 英文關鍵字： Phase Transfer Catalysis; Kinetics; Synthesis; Allylation Of 2,4-Dibromophenol; Apparent Reaction Rate