同核双卤分子X_2(X=F,Cl,Br,I)与C_2H_2相互作用本质的量子化学研究  

Theoretical study on the nature of X_2(X=F, Cl, Br, I) and C_2H_2 Interactions

作　　者：罗骏[1] 李晓凤[1] 曹茂启 代虹镜[1] 曾承露[1] 

机构地区：[1]黔南民族师范学院化学与化工系,贵州都匀558000

出　　处：《分子科学学报》2017年第1期55-61,共7页Journal of Molecular Science

基　　金：贵州省科学技术基金资助项目(黔科合LH字[2015]7705)

摘　　要：用对称性匹配微扰理论(SAPT)对C_2H_2与X2(X=F,Cl,Br,I)相互作用进行了量子化学研究.优化所得的4个稳定复合物相互作用能在-3.276 8^-10.639 5 k J/mol之间.自然键轨道(NBO)理论分析表明,形成复合物分子间的电荷转移量都很少,在0.002 3~0.013 2之间.SAPT2能量分析显示,从F到I,静电能和诱导能先增大后减小,交换能和色散能逐渐增强,相互作用能依次增强.复合物稳定构型的相互作用能中静电能占主导作用,对吸引能的贡献比例在C_2H_2 F2中最大(57.3%),在C_2H_2 I2中最小(49.7%);其次为色散能,在吸引能中所占的比例在21.9%(C_2H_2 F2)~31.2%(C_2H_2 I2)之间;诱导能在吸引能中所占的比例最小,均小于20.7%.The interactions of X_2（X=F, Cl, Br, I） and C_2H_2 were investigated at the MP2 level by using symmetry-adapted perturbation theory. Four stable complexes, the interaction energy between-3.276 8 and-10.639 5 k J/mol were obtained. The natural bond orbital（NBO） analysis reveals that the intermolecular charge-transfer of these cpmplexes is little, which lies in 0.002 3 and 0.012 3. The symmetry adapted perturbation theory（SAPT） calculations were carried out to decompose the binding energy of these complexes into individual interaction energy components. The results show that the electrostatic energies and induction energies firstly increases and then decreases from F to I, but the exchange energies and dispersion energies increase gradually, the sum of these interaction energy components gradually increases. In the stable structures, the electrostatic energy is the dominant, and the contribution for the attractive interaction energies is largest of 57.3% in C_2H_2…F2 and the smallest of 49.7% in C_2H_2…I2. Then the contribution of dispersion energies to the attractive interaction energies is in the range of 21.9%（C2H2…F2）~31.2%（C_2H_2…I_2）; the smallest is the induction energies, less than 20.7%.

关 键 词：分子间相互作用 对称性匹配微扰理论(SAPT) 乙炔 双卤分子 

分 类 号：O641[理学—物理化学]