摘要
用abinitioHF/ 6 3 11+ +G 计算求得叠氮乙烷二聚体势能面上三种优化构型和电子结构 .经MP2电子相关校正和基组叠加误差 (BSSE)以及零点能 (ZPE)校正 ,求得分子间最大相互作用能为 -10 .45kJ/mol.二子体系间的电荷转移很少 .由自然键轨道 (NBO)分析揭示了相互作用的本质 .基于统计热力学求得温度为 2 0 0 .0 0～80 0 .0
Energetic materials are aggregative and mixed syst em s. The intermolecular interactions play significant roles in the physical, chemi cal and explosive property. The study on intermolecular interactions of energeti c materials has attracted wide attention. The organic azides are an important ca tegory of energetic materials and widely used in many fields. Ethyl azide is the simple model having the explosive property for the organic azides energetic com pound. Ethyl azide monomer (Ⅰ) and all its possible stable clusters (Ⅱ,Ⅲ and Ⅳ) are fully optimized by ab initio method at the HF/6-311++G * * level. Vibrational frequencies calculated to ascertain each structure are characterized to be the stable structure (no imaginary frequencies). The pro portions of correlated interaction energies to their total interaction energies ΔE(MP2) are 65.14%, 63.76% and 65.62% for Ⅱ, Ⅲ and Ⅳ respectively. In a ddition, the basis set superposition error (BSSE) correction energies are 7.82, 7.61 and 4.40 kJ/mol for Ⅱ, Ⅲ and Ⅳ respectively. The zero point energy (ZPE) corrections for the interaction energies are much less than those of MP2 electr on correlation and BSSE correction energies. After MP2 electron correlation corr ection, BSSE and ZPE correction, the greatest corrected intermolecular interacti on of the dimers is -10.45 kJ/mol. The charge redistribution mainly occurs on th e adjacent N…H atoms between submolecules. The charge transfer between two subs ystems is very small. Natural bond orbital (NBO) analysis is performed to reveal the origin of the interaction. Based on the statistical thermodynamic method, t he standard thermodynamic functions, heat capacities (C 0 p), entropies ( S 0 m) and enthalpies (H 0 m) and the changes of thermodynamic prope rties from the monomer to dimer with the temperatures ranging from 200.00 K to 8 00.00 K have been obtained.
基金
ProjectsupportedbytheNationalNaturalScienceFoundationofChina (20173028)andtheCommissionofScienceTechnologyandIndustryforNationalDefense
