【作者】 包杰；

【导师】 梅付名；

【作者基本信息】 华中科技大学 ， 物理化学， 2008， 硕士

【摘要】 苯氨基甲酸酯(MPC)是一种重要的有机原料及中间体,特别是可用于合成聚氨酯的原料——二苯甲烷二异氰酸酯(MDI)。传统合成MPC主要采用光气法,其过程不可避免的出现使用高毒性的光气、反应产生腐蚀性大的氯化物和大量废液等问题,严重污染环境和腐蚀设备。羰基化法被认为是目前最有前途的合成MPC非光气方法,但是目前该法都使用了价格昂贵的贵金属作为均相催化剂,催化剂难以回收再用,反应成本高,环境污染严重。本文合成了封装钴希夫碱配合物,并将其作为催化剂用于苯胺氧化羰化合成MPC的反应中,探寻到了一条MPC的绿色合成途径。本文主要工作与结论是:1、合成六种salen和salophen配体,与醋酸钴反应配合得到六种Co(Ⅱ)希夫碱配合物。采用“瓶中造船“和自由配体法将六种Co(Ⅱ)希夫碱配合物封装在NaY分子筛超笼中;用AAS, BET, IR, UV-Vis, TGA, XRD和XPS对封装催化剂进行了表征,表征结果证明Co(Ⅱ)希夫碱配合物成功封装在了分子筛的超笼中。2、将封装的Co(Ⅱ)希夫碱配合物催化体系用于苯胺的氧化羰化合成苯胺基甲酸甲酯的反应。考察了配体取代基的电子效应、温度、初始总压、CO初始分压等因素对反应的影响。在六种封装催化剂中,Co(II)salophen(OH)2-Y表现出最好的催化活性。在温度170℃,起始总压为4 MPa,起始分压之比CO:O2为9,封装催化剂Co(II)salophen(OH)2-Y 0.5g,助催化剂KI 0.365g,苯胺11 mmol,无水甲醇25mL,反应3h,苯胺的转化率为67.1%,MPC选择性为77.3%。3、考察了Co(II)salophen(OH)2-Y重复使用5次的催化活性,发现经5次重复使用后,催化剂的催化活性基本保持不变。更多还原

【Abstract】 Methyl N-phenylcarbamate (MPC) is an important organic raw material and intermediate. It can be used as a raw material for the synthesis of methylene diphenyl diisocyanate (MDI). The traditional method for the synthesis of MPC uses phosgene. Highly toxic phosgene, corrosive hydrogen chloride and a large amount of contaminative solution are inevitably involved in this process, which causes serious environmental pollution and equipment corrosion. The preparation of MPC by carbonylation reaction is considered to be the most promising non-phosgene approach, but the use of the expensive noble metals as homogeneous catalysts in this non-phosgene process leads to the difficulty of recycling catalyst and the high cost.In this thesis, a green process for the synthesis of MPC by the oxidative carbonylation of aniline over encapsulated Co (salen) was studied. Conclusions presented in this thesis were summarized as follows:1. Six salen ligands and six Co (salen) complexes were synthesized. Co (salen) complexes were successfully encapsulated in zeolite Y by“shipping-in-bottle”and flexible ligand method. The heterogeniged catalysts were characterized by AAS, BET, IR, UV-Vis TGA, XRD and XPS.2、The catalytic activities of the encapsulated catalysts and their homogeneous analogues were examined in the oxidative carbonylation of aniline to MPC. The effects of the electronic-effects of the substituent group, temperature, initial total pressure and CO initial pressure on the reaction were investigated. Under the conditions of aniline (11 mmol), encapsulated catalyst (0.5g), KI (0.365g), CO/O2 ratio 9:1, 4MPa, 170oC, 3h, Co(II)salophen(OH)2-Y catalyst shows the highest activity with the conversion of aniline 67.1% and selectivity of MPC 77.3%, respectively.3、The performance of recovered Co(II)salophen(OH)2-Y catalyst under the same conditions was studied, and we found that Co(II)salophen(OH)2-Y could be at least recycled for five times and no significant loss of catalytic activity was observed.更多还原