Quantum Chemistry Group, Department of Chemistry, Faculty of Sciences, Arak University, Arak 38156-8-8349, Iran.
J Phys Chem A. 2012 May 31;116(21):5199-206. doi: 10.1021/jp300540z. Epub 2012 May 16.
Quantum calculations at the MP2/cc-pVTZ, MP2/aug-cc-pVTZ, and CCSD(T)/cc-pVTZ levels have been used to examine 1:1 and 1:2 complexes between O(2)NX (X = Cl, Br, and I) with NH(3). The interaction of the lone pair of the ammonia with the σ-hole and π-hole of O(2)NX molecules have been considered. The 1:1 complexes can easily be differentiated using the stretching frequency of the N-X bond. Thus, those complexes with σ-hole interaction show a blue shift of the N-X bond stretching whereas a red shift is observed in the complexes along the π-hole. The SAPT-DFT methodology has been used to gain insight on the source of the interaction energy. In the 1:2 complexes, the cooperative and diminutive energetic effects have been analyzed using the many-body interaction energies. The nature of the interactions has been characterized with the atoms in molecules (AIM) and natural bond orbital (NBO) methodologies. Stabilization energies of 1:1 and 1:2 complexes including the variation of the zero point vibrational energy (ΔZPVE) are in the ranges 7-26 and 14-46 kJ mol(-1), respectively.
在 MP2/cc-pVTZ、MP2/aug-cc-pVTZ 和 CCSD(T)/cc-pVTZ 水平上进行了量子计算，以研究 O(2)NX（X = Cl、Br 和 I）与 NH(3)之间的 1:1 和 1:2 络合物。考虑了氨的孤对与 O(2)NX 分子的 σ-hole 和 π-hole 的相互作用。可以使用 N-X 键的伸缩频率轻松区分 1:1 络合物。因此，具有 σ-hole 相互作用的那些络合物显示 N-X 键伸缩的蓝移，而在沿 π-hole 的络合物中观察到红移。SAPT-DFT 方法已用于深入了解相互作用能的来源。在 1:2 络合物中，使用多体相互作用能分析了协同和微弱的能量效应。使用分子中的原子（AIM）和自然键轨道（NBO）方法对相互作用的性质进行了表征。包括零点振动能（ΔZPVE）变化在内的 1:1 和 1:2 络合物的稳定能分别在 7-26 和 14-46 kJ mol(-1)范围内。
