甲苯-2,4-二异氰酸酯与仲胺类化合物反应中的质子转移过程(英文)  

Proton Transfer in Reaction between 2,4-Diisocyanatotoluene and Amine Compounds

作　　者：王晓轩[1] 胡伟[2] 贵大勇[1] 池旭辉[2] 王明良[1] 田德余[1] 刘剑洪[1] 马新刚[2] 庞爱民[2] 

机构地区：[1]深圳大学化学与化工学院,广东深圳518060 [2]湖北航天化学技术研究所,湖北襄樊441003

出　　处：《物理化学学报》2014年第1期34-42,共9页Acta Physico-Chimica Sinica

基　　金：The project was supported by the National Defense Foundation of China(973)(613142);National Natural Science Foundation of China(20673073);Foundation of Shenzhen Key Laboratory of Functional Polymer,China(FP20130007)~~

摘　　要：采用密度泛函理论B3LYP/6-31+G(d,p)方法研究了甲苯-2,4-二异氰酸酯(2,4-TDI)与仲胺类化合物反应过程中的质子转移效应.研究发现甲醇分子对反应有显著的催化效应,可使反应能垒大幅降低,这表明含活泼氢的化合物会加速质子转移过程,从而加快反应速率.2,4-TDI与甲基-N-甲基氨基甲酸酯的催化加成反应为一步反应,其反应过渡态呈六元环结构;而2,4-TDI与N-甲基对硝基苯胺、二苯胺、1,2-二氢-2,2,4-三甲基喹啉等芳香胺类化合物的催化加成反应经历了两步反应,其中第一步为速率控制步骤.研究表明,在与2,4-TDI的反应中,芳胺化合物的活性高于甲基-N-甲基氨基甲酸酯的活性,计算的反应活性顺序与实验结果一致.The effects of proton transfer on the reaction between 2,4-diisocyanatotoluene （2,4-TDI） and active-hydrogen-containing amine compounds were calculated using density functional theory （DFT） at the B3LYP/6-31 ＋G（d, p） level. The energy barriers are significantly reduced when a methanol molecule serves as a proton transporter or a reactive catalyst, indicating that the labile hydrogen-containing compound plays a key role in accelerating the reaction rate and proton transfer. The catalytic addition of 2,4-TDI and methyl N-methylcarbamate follows a one-step mechanism, with a transition state characterized by a six- membered ring. However, the catalytic additions of 2,4-TDI and aromatic amines such as N-methyl-p- nitroaniline, diphenylamine, and 1,2-dihydro-2,2,4-trimethylquinoline involve two steps, with the first step as the rate-limiting step. The reactions between 2,4-TDI and aromatic amines have lower energy barriers than that between 2,4-TDI and methyl N-methylcarbamate. The aromatic amines are more active than methyl N- methylcarbamate in the reaction with 2,4-TDI, which is in a good agreement with experimental results.

关 键 词：密度泛函理论 质子转移 甲苯-2 4-二异氰酸酯 聚氨酯反应 

分 类 号：O621.25[理学—有机化学]