HCN(HNC)与NH_3,H_2O和HF分子间相互作用的理论研究

Theoretical Study on Intermolecular Interactions Between HCN(HNC) and NH_3,H_2O,HF

在MP2/aug-cc-pVTZ水平上,对HCN(HNC)与NH3,H2O和HF分子间可能存在的氢键型复合物进行了全自由度能量梯度优化,通过在相同水平上的频率验证分析发现了稳定的分子间相互作用形式是HCN(HNC)作为质子供体或作为质子受体形成的复合物.基组重叠误差对总相互作用能的影响均小于3.34 kJ/mol.通过自然键轨道(NBO)分析,研究了单体和复合物中的原子电荷和电荷转移对分子间相互作用的影响.对称性匹配微扰理论(SAPT,Symmetry Adapted Perturbation Theory)能量分解结果表明,在分子间相互作用中,静电作用与诱导作用占主导地位,而诱导作用与复合物的电荷转移之间具有良好的正相关性.

Ab initio molecular orbital calculations including MP2 correlation energy was employed to optimize the geometries of the hydrogen-bonded complexes formed by HCN （HNC） with NH3, H2O and HF, respectively at aug-cc-pVTZ level. It was found that there were two kinds of stable complexes bonded by intermolecular hydrogen bonds ： HCN （HNC） as the proton donor and as the proton acceptor. The effect of basis set superposition error on the total interaction energy is smaller than 3.34 kJ/mol. Natural bond orbital （NBO） analysis was performed to analyze the atomic charges and charges transfer in the monomers and complexes. The results of the decomposition of interaction energy according to SAPT2 show that the electrostatic and induction forces dominate the intermolecular interaction, and there is a good correlation between induction forces and charges transfer.