Energy maxima in anionic nucleophilic additions to carbonyl groups: The location of a saddle point for the addition of hydride to formaldehyde
Energy maxima in anionic nucleophilic additions to carbonyl groups: The location of a saddle point for the addition of hydride to formaldehyde
复制标题
羰基阴离子亲核加成的能量最大值：氢化物与甲醛加成的鞍点位置
DOI：
10.1139/v88-023
复制
发表时间：
1988
影响因子：
1.1
通讯作者：
F. Grein
中科院分区：
文献类型：
--
作者：
C. Bayly;F. Grein
使用理论从头算方法重新研究了氢化物与甲醛的阴离子亲核加成得到甲醇化物的反应曲线。使用各种基组（包括带或不带偏振和漫射功能的4-31G和6-31G），并在MP2、MP3和MP4级别进行电子相关计算，并在MP2级别进行几何优化。在向基组添加扩散函数后，局部能量最大值被引入到 SCF 反应曲线中，与之前研究中发现的完全有吸引力的势能曲线相比，曲线特征发生了重大变化。在势垒的反应物一侧，发现能量较低的局部最小值 4.56kcal/mol，对应于离子偶极复合物。随着电子相关性的加入，局域势垒几乎消失，离子偶极复合物与势垒最大值之间的能量差减小到小于1kcal/mol。此外，该地...
The reaction profile of the anionic nucleophilic addition of hydride to formaldehyde giving methanolate was re-investigated using theoretical ab initio methods. A variety of basis sets (including 4-31G and 6-31G with and without polarization and diffuse functions) were used, and electron correlation calculations were performed at the MP2, MP3, and MP4 levels with geometry optimizations at the MP2 level. Upon the addition of diffuse functions to the basis set, a local energy maximum was introduced into the SCF reaction profile, a major change in the character of the profile compared to the entirely attractive potential energy curve found in previous studies. On the reactants side of the barrier a local minimum 4.56 kcal/mol lower in energy was found, corresponding to an ion–dipole complex. With the inclusion of electron correlation, the local barrier almost disappeared, with the energy difference between the ion–dipole complex and the barrier maximum decreasing to less than 1 kcal/mol. Furthermore, the loc...