论文部分内容阅读
用从头计算法研究了乙烯酮与乙烯(或乙炔)环加成反应机理.所有的几何构型优化都采用能量梯度法(在STO-3G水平上).对过渡态结构都用分析力常数矩阵计算进行了确证。为了得到较好的反应位垒和生成热,在HF/STO-3G结构参数基础上。采用MP2/6-31G和MP3/6-31G作了单点能量计算。计算结果表明,这2个反应都按协同、非同步的方式进行。乙烯酮与乙烯和乙炔环加成反应的活化位垒分别为244.2和294.5kJ/mol。
The ab initio method was used to study the cycloaddition reaction of ketene with ethylene (or acetylene). All geometric configurations were optimized using the energy gradient method (at the STO-3G level). For transition state structures, the analytical force constant matrix Computation was confirmed. In order to get a good reaction barrier and heat generation, based on HF / STO-3G structural parameters. Using MP2 / 6-31G and MP3 / 6-31G made a single point of energy calculation. The calculation results show that these two reactions are conducted in a coordinated and asynchronous manner. The activation barriers for the addition reaction of ketene with ethylene and acetylene were 244.2 and 294.5 kJ / mol, respectively.