• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >On the nature of stabilization in weak, medium, and strong charge-transfer complexes: CCSD(T)/CBS and SAPT calculations
【24h】

On the nature of stabilization in weak, medium, and strong charge-transfer complexes: CCSD(T)/CBS and SAPT calculations

机译：关于弱，中和强电荷转移络合物的稳定性质：CCSD（T）/ CBS和SAPT计算

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Weak, medium, and strong charge-transfer (CT) complexes containing various electron donors (C_2H_4, C_2H_2, NH _3, NMe_3, HCN, H_2O) and acceptors (F _2, Cl_2, BH_3, SO_2) were investigated at the CCSD(T)/complete basis set (CBS) limit. The nature of the stabilization for these CT complexes was evaluated on the basis of perturbative NBO calculations and DFT-SAPT/CBS calculations. The structure of all of the complexes was determined by the counterpoise-corrected gradient optimization performed at the MP2/cc-pVTZ level, and most of complexes possess a linear-like contact structure. The total stabilization energies lie between 1 and 55 kcal/mol and the strongest complexes contain BH3 as an electron acceptor. When ordering the electron donors and electron acceptors on the basis of these energies, we obtain the same order as that based on the perturbative E2 charge-transfer energies, which provides evidence that the charge-transfer term is the dominant energy contribution. The CCSD(T) correction term, defined as the difference between the CCSD(T) and MP2 interaction energies, is mostly small, which allows the investigation of the CT complexes of this type at the "cheap" MP2/CBS level. In the case of weak and medium CT complexes (with stabilization energy smaller than about 15 kcal/mol), the dominant stabilization originates in the electrostatic term; the dispersion as well as induction and δ(HF) terms covering the CT energy contribution are, however, important as well. For strong CT complexes, induction energy is the second (after electrostatic) most important energy term. The role of the induction and δ(HF) terms is unique and characteristic for CT complexes. For all CT complexes, the CCSD(T)/CBS and DFT-SAPT/CBS stabilization energies are comparable, and surprisingly, it is true even for very strong CT complexes with stabilization energy close to 50 kcal/mol characteristic by substantial charge transfer (more than 0.3 e). It is thus possible to conclude that perturbative DFT-SAPT analysis is robust enough to be applied even for dative-like complexes with substantial charge transfer.
机译：在CCSD（T ）/完整基准集（CBS）限制。这些CT复合物的稳定化性质是根据​​扰动NBO计算和DFT-SAPT / CBS计算进行评估的。所有配合物的结构都是通过在MP2 / cc-pVTZ水平进行的平衡平衡梯度优化确定的，大多数配合物都具有线性接触结构。总稳定能在1至55 kcal / mol之间，最强的配合物含有BH3作为电子受体。当基于这些能量对电子供体和电子受体进行排序时，我们获得的阶数与基于微扰的E2电荷转移能级的阶数相同，这提供了电荷转移项是主要的能量贡献的证据。 CCSD（T）校正项（定义为CCSD（T）和MP2相互作用能之差）大部分很小，这使得可以在“便宜的” MP2 / CBS级别研究此类CT复合体。对于弱而中等的CT络合物（稳定能小于约15 kcal / mol），主要的稳定作用源自静电项。然而，涵盖CT能量贡献的色散，感应和δ（HF）项也很重要。对于强CT络合物，感应能量是第二大（仅次于静电）最重要的能量项。感应和δ（HF）项的作用是CT络合物的独特特征。对于所有CT复合物，CCSD（T）/ CBS和DFT-SAPT / CBS稳定化能量都是可比的，而且令人惊讶的是，即使对于非常坚固的CT复合物，其稳定能量接近50 kcal / mol（通过大量电荷转移）的特性也是如此（大于0.3 e）。因此，有可能得出结论，微扰DFT-SAPT分析足够强大，甚至可以应用于具有大量电荷转移的类似类化合物的复合物。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号