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THEORETICAL STUDY FOR ELECTRONIC STRUCTURES OF THE DIMER CATIONS OF AROMATIC COMPOUNDS

芳香族化合物二聚体阳离子电子结构的理论研究

基本信息

批准号：
11640519
负责人：
MIYOSHI Eisaku
金额：
$ 2.18万
依托单位：
KYUSHU UNIVERSITY (2000)Okazaki National Research Institutes (1999)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11640519/
关键词：
Molecular Orbital Theory Benzene Trimer Cation Phenol Dimer Cation OH Vibrational frequency 芳香族分子2量体カチオン MRSDCI計算

项目摘要

Recently, we showed using ab initio MO calculations at levels of CASSCF and MRSDCI that the global minimum of the benzene dimer cation, (C_6H_6)_2^+, are at distorted sandwich C_<2h> geometries, which is lower than sandwich D_<6h> and T-shaped C_<2v> structures by 0.016 and 0.162 eV, respectively. In this study, we performed similar calculations for the benzene trimer cation, (C_6H_6)_3^+, and found that that the global minimum of the trimer cation is the distorted C_<2v> sandwich structure, which is 0.032 eV lower than the D_<6h> sandwich structure. The dissociation energy (D_e). relative to (C_6H_6)_2^++C_6H_6 was calculated to be 0.43 eV, in comparison to the experimental value (D_0) of 0.34±0.02 eV.Our calculations revealed that most of the charge of the trimer cation is localized in the central benzene ring, whose gross charge is +0.9. This observation contrasts with speculations by experimentalists that the charge is localized in the dimer core or delocalized over all three benze … More ne rings.We investigated also possible geometrical structures for the phenol dimer and its cation. The calculated binding energy of the phenol dimer reasonably agrees with experimental and other theoretical values. The calculated binding energies of the dimer cation are about 28 kcal/mol at the MP2 and CASSCF levels ; this is more than three times larger than in the neutral dimer. The OH stretching frequencies (3616〜3618 cm^<-1>) of the PAP in the phenol dimer cation are in good agreement with the observed value (3620±3 cm^<-1>). Those of the PDP in the dimer cation are calculated to be 2434〜2447 cm^<-1>, which are 1210〜1223 cm^<-1> smaller than that of bare phenol. The large reduction of the OH stretching frequency of the PDP in the phenol dimer cation can be attributed to elongation of the 0-H bond involved in the hydrogen bond on the formation of a stronger hydrogen bond in the cation than in the neutral dimer. These values for the OH stretching frequencies of the PDP in the phenol dimer cation will serve for future reference. Less

最近，我们用从头计算方法在CASSCF和MRSDCI水平上发现，苯二聚体阳离子（C_6H_6）_2 ^+的全局最小值位于扭曲的三明治C_构型，比三明治D_构型和三明治T_构型分别低0.016和0.162 eV。<2h><6h><2v>在本研究中，我们对苯三聚体阳离子（C_6H_6）_3 ^+进行了类似的计算，发现三聚体阳离子的全局最小值是畸变的C_sandwich结构，比D_sandwich结构低0.032 eV。<2v><6h>离解能（D_e）。相对于（C_6H_6）_2 ^++ C_6H_6的D_0为0.43 eV，而实验值为0.34 ± 0.02 eV。计算结果表明，三聚体阳离子的大部分电荷集中在中心苯环上，其总电荷为+0.9。这个观察结果与实验学家的推测相反，实验学家推测电荷是定域在二聚体核中，或者是在所有三个苯上离域的。 ...更多信息 ne环。我们还研究了苯酚二聚体及其阳离子的可能几何结构。苯酚二聚体的结合能的计算值与实验值和其他理论值相当一致。在MP2和CASSCF水平下，二聚体阳离子的计算结合能约为28 kcal/mol;这比中性二聚体大三倍以上。PAP在苯酚二聚体阳离子中的OH伸缩频率（3616 ± 3618 cm ^）与观察值（3620 ± 3 cm ^）非常一致。<-1><-1>二聚体阳离子中PDP的那些被计算为2434 × 2447 cm ↑ [2]，其比裸苯酚的那些小1210 × 1223 cm ↑ [2]。<-1><-1>PDP在苯酚二聚体阳离子中的OH伸缩频率的大幅度降低可以归因于在阳离子中形成比中性二聚体中更强的氢键时参与氢键的O-H键的伸长。在苯酚二聚体阳离子中PDP的OH伸缩频率的这些值将用于将来的参考。少