臺灣博碩士論文加值系統

本論文的研究目的是針對由甲苯/溴化銨鹽/酚化鈉與氫氧化鈉水溶液所構成之相間轉移觸媒系統，進一步瞭解第三液相成因及三液相相間轉移催化之反應機構。
在針對此一系統之研究中，發現除了以溴化正己基銨鹽外，其它Prop4NBr、Bu4NBr、Hex4NBr、Octyl4NBr等溴化四級銨鹽均會有第三液相出現。根據此一研究結果，我們可將這幾種銨鹽，歸納成二類，由這二類銨鹽形第三液相的原因不同。第一類為親水性四級銨鹽，形成第三液相最主要的原因，是加入氫氧化鈉後鹽析作用所致。此外，溴化正四丁基銨所組成的系統，當加入氫氧化鈉後，會出現逆萃取的現象。經由前人的發表及實驗結果，推測是因酚化鈉水解成酚，而使得QOPh與HOPh形成QOPh‧(HOPh)n。的結構，致使QOPh在甲苯中的濃度提昇。第二類為親油性四級銨鹽，形成第三液相的主要原因是甲苯相中生成帶有離子性複合物。
由IR的光譜，得知存在於甲苯中的鹼是酚化鈉，並非是氫氧化鈉，若甲苯層中出現過量的鹼時，我們也測出甲苯中的水含量會明顯的增加。此一結果，顯示水進入甲苯中與甲苯中含酚化鈉有關。所以推測此刻甲苯中應含有QOPh‧(H2O)m‧(NaOPh)n的複合物。又由Na23的NMR光譜結果，發現親油性銨鹽所形成的系統中甲苯層內之Na有兩種狀態，一為離子性鈉 ，二為鍵結性鈉。由此可知QOPh‧(H20)m‧(NaOPh)n複合物是有離子性的。所以很可能是促成親油性銨鹽形成第三液相的原因。
溫度也是影響形成第三液相的因素，而溫度對兩類銨鹽形成第三液相的影響不同。對親油性銨鹽，當溫度升高，第三液相會消失；而親水性銨鹽，溫度對它的影響恰恰相反。
綜合截至目前對第三液相的認知，我們認為三液相相間轉移催化反應，並不是以離子對的方式進行催化反應，而應該是四級銨鹽之陰離子直接與受質進行催化反應。因此，我們提出與微胞相似的反應機構模式。模式顯示，反應可能成為零階，而實驗結果也是如此。

This study amied at the formation of a third liquid phase and the reaction kinetics in the third liquid phase formed in the systems of toluene/R4NBr/(NaOPh+NaOH) aqueous solution.
By a series of experiments, we have found that all symmetric quaternary ammonium bromides, except for Et4NBr, can form a third liquid phase. These symmetric quaternary ammonium salts can be classified into two types, hydrophilic and hydrophobic (lipophilic). In the system containing a hydrophihc salt, the third liquid phase was formed by salting-out effect with adding NaOH. Note that reverse extraction was observed in the system containing Bu4NBr. Referring to the result obtained by Angrawals et al., we know that this phenomenon is attributed to the formation of QOPh.(HOPh)n complex, in which phenol is formed by he hydrolysis of NaOPh. The formation this complex can enhance the solubility of QOPh in toluene. The formation of a third liquid phase in the system containing a hydrophobic salt is due to the formation of an ionic complex in toluene as explained in the following.
From the IR spectrum, we know that the base complex in the toluene phase contains NaOPh, not NaOH. When an excess amount of base was found in toluene, more water was measured in the same phase. These two observations suggest the formation of QOPh.(H2O)n.(NaOPh)m complex in toluene. Futhermore, Na23 NMR spectrum shows that Na in this complex is of two types, ionic and nonionic (covalent). This fact implies that this complex might have ionic property which induce the formation of a third liquid phase.
Temperature affects the formation of a third liquid phase in two different ways, depending the kind of quaternary ammonium salt. Low temperature is beneficial the formation of a third phase for a system containing a hydrophobic salts, whereas high temperature is advantageous that containing a hydrophilic one.
From the observation on the composition of a third liquid phase, we consider that the SN2 reaction in the third liquid phase is not by quaternary ammonium ion pair, instead, is by the free anion. Therefore, we adopt a micelle-like mechanism to delineate the reaction in the third hquid phase. The reaction rate expression that derived is of a zero order form. Experiment result confirmed this kinetic model.