炸药敏化剂的分子结构、电子结构和生成热的理论研究

在HF/6-31G*和B3LYP/6-31G*基组水平上, 对硝酸乙酯(EN)、硝酸正丙酯(NPN)、硝酸异丙酯(IPN)、硝酸异辛酯(EHN)和四甘醇二硝酸酯(TEGDN)五种炸药敏化剂进行理论计算, 研究了标题物的分子结构、电子结构和能量等方面的性质. 基于Mulliken布居和键长分析, 五种硝酸酯分子的热分解始于O2—N3键的断裂, 且由Mulliken电荷分布推知分子热解产生NO2气体. 在分析前线轨道能(EHOMO, ELUMO)和能量差(ΔE)的基础上对五种硝酸酯的相对热稳定性大小进行了评估. 由等键反应获得的EN、IPN、NPN、EHN和TEGDN的标准生成热分别是-155.972、-190.896、-175.279、-272.376和-790.733 kJ·mol-1.

Molecular Structure, Electronic Structure and Heats of Formation of Explosive Sensitizers

Quantum chemical calculations at the HF/6-31G* and B3LYP/6-31G* levels have been carried out on five explosive sensitizers: ethyl nitrate (EN), n-propyl nitrate (NPN), isopropyl nitrate (IPN), 2-ethylhexyl nitrate (EHN),and tetraethylene glycol dinitrate (TEGDN). Theoretical studies have yielded a wealth of quantum chemical information on the molecular geometries, electronic structures, and energies of the title compounds. On the basis of the Mulliken populations and bond lengths, the O2-N3 fission is acceptable. Charge distribution analysis indicated that the five nitrates produced NO2 gas during the dissociation of the O2-N3 weak bond. The relative thermal stability ordering of the five nitrates was estimated on the basis of the frontier orbital energy (EHOMO, ELUMO) and the energy gap (△E). The heats of formation (HOFs) of the five sensitizers, EN, IPN, NPN, EHN, and TEGDN, were calculated from the isodesmic reactions and were-155.972,-190.896,-175.279,-272.376,and –790.733 Kj·mol-1,respectively.