Tian Shan Xi, Li Hai-Bei
Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.
J Phys Chem A. 2007 May 24;111(20):4404-10. doi: 10.1021/jp070730u. Epub 2007 Apr 27.
Three low-lying conformers of the hydrogen maleate anions (HMAs) regarding cis-HMA(HB) having the O-...HO intramolecular hydrogen bond (HB), cis-HMA(nHB) without the HB, and trans-HMA are studied by density functional theory (B3LYP) combined with natural bond orbital (NBO) and atoms-in-molecules (AIM) analyses. The photoelectron spectra of cis- and trans-HMA conformers recorded by Woo et al. (J. Phys. Chem. A 2005, 109, 10633) are reassigned on the basis of the present electron propagator theory calculations, indicating the significant energy differences between the Dyson orbitals and canonical molecular orbitals due to the electron-correlation and orbital relaxation effects considered in the electron propagator theory. The NBO associated with the natural resonance theory analyses and AIM electron topological study show that the strong O-...HO in cis-HMA(HB) has the remarkable characteristics of three-center four-electron hyperbond, and the bonding strength of ca. 30 kcal/mol is recommended with the reference calculations of the HO-...HOH complex. The further calculations for the microhydrated cis-HMA(HB) clusters indicate that the O-...HO bonding strength decreases in water solution.
通过密度泛函理论（B3LYP）结合自然键轨道（NBO）和分子中的原子（AIM）分析，研究了顺式马来酸氢根阴离子（cis-HMA(HB)）、无分子内氢键（HB）的顺式马来酸氢根阴离子（cis-HMA(nHB)）和反式马来酸氢根阴离子（trans-HMA）的三种低位构象。基于目前的电子传播理论计算，对Woo等人（《物理化学杂志A》，2005年，109卷，10633页）记录的顺式和反式HMA构象的光电子能谱进行了重新分配，这表明由于电子传播理论中考虑的电子相关和轨道弛豫效应，戴森轨道和正则分子轨道之间存在显著的能量差异。与自然共振理论分析相关的NBO和AIM电子拓扑研究表明，顺式HMA(HB)中强的O-...HO具有三中心四电子超键的显著特征，参考HO-...HOH络合物的计算结果，建议其键合强度约为30 kcal/mol。对微水合顺式HMA(HB)团簇的进一步计算表明，在水溶液中O-...HO键合强度降低。
