CAJ | 학술논문

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.
채용밀도범함이론B3LYP/6-31+G(d, p)방법연구료갑분-2,4-이이청산지(2,4-TDI)여중알류화합물반응과정중적질자전이효응.연구발현갑순분자대반응유현저적최화효응,가사반응능루대폭강저,저표명함활발경적화합물회가속질자전이과정,종이가쾌반응속솔.2,4-TDI여갑기-N-갑기안기갑산지적최화가성반응위일보반응,기반응과도태정륙원배결구；이2,4-TDI여N-갑기대초기분알、이분알、1,2-이경-2,2,4-삼갑기규람등방향알류화합물적최화가성반응경력료량보반응,기중제일보위속솔공제보취.연구표명,재여2,4-TDI적반응중,방알화합물적활성고우갑기-N-갑기안기갑산지적활성,계산적반응활성순서여실험결과일치.
The effects of proton transfer on the reaction between 2,4-di socyanatotoluene (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 fol ows 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.