【作者】 刘晓忠；

【导师】 金子林；

【作者基本信息】 大连理工大学 ， 应用化学， 2001， 博士

【摘要】 贵金属催化剂的分离与回收一直是均相络合催化工业化的一个关键问题。过去二十年来，为解决这一问题，越来越多的研究集中在将催化剂固载在高分子或无机载体上，或将催化剂动态担载在与产物不互溶的流动相等称之为“均相催化剂的多相化”上，并已经取得了令人振奋的成果。本课题组最近提出的“温控相转移催化”正是这一领域的最新进展之一。 本文基于温控相转移催化理论，设计、合成了一类具聚醚链的非离子亚磷酸酯型膦配体OPGPP，在聚醚链的长度与亲油基大小匹配时，此类配体具逆反温度-水溶性特性——浊点。浊点温度的高低取决于分子结构中的亲水基即聚醚链的长度和亲油基的大小。研究还发现，某些无机盐的加入会降低配体浊点，浊点降低的大小跟加入无机盐的种类和量有关。 研究中设计了烯丙醇的常压水相加氢反应动力学来考察OPGPP与Rh形成的配合物催化剂的“逆反温度-水溶性”特性。发现反应过程中出现了反Arrhenius现象，当反应温度升高到浊点温度以上时，非离子水溶性膦配体铑催化剂会从水相析出而导致加氢速率的急剧下降。这一结果表明，OPGPP的浊点特性在一定温度范围内，会引起体系的相变，从而导致其过渡金属配合物产生特殊的“温控催化”过程。 依据温控相转移催化理论，具有浊点特性的配合物在水/有机两相体系中高于浊点的反应温度下，会从水相析出进入有机相催化反应进行，在反应结束后，温度降到浊点以下时，催化剂重返水相与产物分离。基于OPGPP的浊点性能，本文将OPGPP的铑配合物应用于催化水/有机两相1-正癸烯的氢甲酰化反应。详细考察了溶剂、反应时间、温度、压力、膦/铑比等各种因素对催化反应的影响。在反应条件Sub/Rh=1000，P/Rh=13，80℃，5.OMpa，反应3小时，烯烃转化率、醛收率均达95％以上，产物正/异比为0.91，经简单相分离，催化剂可循环使用，但经3次循环催化剂活性有明显下降。进一步实验发现，催化剂催化剂活性的下降主要与配体的水解有关。 为避免配体的水解，本文对在有机溶剂中的溶解性及其铑配合物在单有机相中高碳烯烃氢甲酰化的催化性能进行了研究。研究发现，上述配体在某些有机溶剂中呈现高温溶解、低温析出的温变特性。配体在有机溶剂中析出的程度跟聚醚链长度和溶剂有关。利用ICP-AES技术测定了不同长－－－－－－－－－－－－－－－－－－ n度聚醚链的offiPP配体在不同有机溶剂中的溶解度。结果表明，低温下配体在非极性的烷烃中溶解度极低。将配体的这种温变特性用于均相催化反应，郁猕为分离回收催化剂的另飞径。研究表明，opoPP／Rh可剜地应用于催化无水存在的单有机相卜正癸烯氢甲酚化反应，在优化的反应条件：SUb／Rh＝1000，P／Rh＝13，90C，5．OMPa，反应4 ’J’时，烯烃转化率、醛收率均达95％以上，产物U异比为0 94。反应结束后，催化齐几乎全部析出，经简单倾倒分离，催化剂经循环使用6次，催化活性基本不变。 侧叩爪U／m＼应用于单有机相催化体系中卜癸烯的氢甲酚化反应时，催化剂呈现高的活性，可以简易分离，经3次循环使用卜癸烯转化率仍保持在87％以上。 将opoP升Rh催化剂用于单有伽肿三聚丙烯氢甲酞化反应，催化齐也表现较高的活性。当反应条件为130oC，6．0 MPa，P／Rh＝13和S／Rh＝500时，反应gb可使烯烃转化率和醛收率MIJAfu76．1％和 74．4％。催化剂经循环使用3次，催化Stys性基本不变。更多还原

【Abstract】 One key challenge in the commercial development of homogeneous catalysis has always been the separation of precious metal catalyst from the product. In the past decades ever-increasingly efforts to immobilize catalyst on polymeric or inorganic supports and heterogenise the catalyst and product into separate and immiscible phases have been taken in the direction to tackle this problem, and exciting achievements have been obtained. A novel concept of Thermoregulated Phase-Transfer Catalysis (TRPTC) recently proposed by our research group was just one of the exciting advancement in this areaOn the basis of TRPTC principle, a novel nonionic water-soluble phosphite derived by polyalkylene glycol (OPGPP) was synthesized in the paper. Introduction of certain length of polyoxyethylene moities to the phosphites bestows them with a function of inverse temperature-dependent water solubility and the phosphites gave clear cloud points.The cloud points of the phosphites are dependent on the hydrophile to hydrophobe ratio of the molecule. Addition of certain inorganic salt to aqueous phosphite solution will decrease cloud points of the solution.From the curve of addition quantity of inorganic salt via the cloud points, some cloud points above 100癈 can be deduced.The aqueous phase hydrogenation of allyl alcohol under atmospheric pressure is designed in order to investigate the role of the cloud point in catalytic reactivities.Because of the inverse temperature-dependent water solubility of polyether-substituted water-soluble ligands, an interesting anti-Arrhenius kinetic behavior has been observed. When the reaction system is heated to a temperature above the cloud point nonionic water-soluble phosphine modified rhodium catalyst will precipitate from the aqueous phase ,which drastically reduces the reaction rate of hydrogenation.Such a result suggests that the cloud point property of polyether-substituted nonionic water-soluble phosphines has a remarkable effect on the catalytic behaviors of their transition metal complexes.According to the principle of TRPTC, Rh complexes modified with polyalkyl glycol ether derived phosphine could precipitate from the aqueous phase at a temperature higherthan Cp of the phosphine and then transfer into organic phase to catalyze the reaction. After the reaction, the complexes return to the aqueous phase and separated by simple phase separation at a temperature below Cp and could be employed in the successive reaction runs. The above OPGPP modified rhodium was applied in the aqueous biphasic hydroformylation of higher alpha-olefins. On the conditions of Sub/Rh=1000,P/Rh=13,80癈,5.0Mpa,the reaction could be completed in 3 hours.The conversions of various olefins are higher above 95% with yields of aldehyde of above 95% and ratios of normal aldehyde to iso-aldehyde 0.6 to 2.0.Catalyst can be easily separated from the product but the catalytic activity of the catalyst decreased sharply in the fourth reaction run. When ratio of P/Rh increased to 50, catalyst recycling was improved markedly.31P-NMR was employed to analyze the aqueous OPGPP solution after keeping for 72 hours at 80癈 and completely hydrolysis was proved .Hence decrease of the catalytic activity of the above catlyst was mainly probably due to the hydrolysis of the P-O-C bond of the phosphite in the presence of water.Farther study the property of OPGPP was done in the paper .It was found that OPGPP could dissolve in some hot organic solvents but it precipitated from the solution when cooling to room temperature.ICP technique was applied to determine the solubility of OPGPP in the solvent at different temperature. The results indicated a very low solubility of OPGPP in some alkanes at a low temperature. When OPGPP/Rh complex was applied to catalyse the hydroformylation of 1-Decene in absence of water, the reaction could be finished in 4 hours on the optimal conditions:Sub/Rh=1000,P/Rh=13,90 癈 ,5.0Mpa .Conversion of olefin and yield of aldehyde are higher above 95% with a ratio of normal aldehyde to iso-aldehyde of 0.94.T更多还原