基于TDDFT的四种含能化合物分子在紫外光下的响应  

The Response of Four Energetic Compound Molecules to Ultraviolet Light Using TDDFT

作　　者：索成翔 关梦雪 王锋 刘瑞斌[4] 郭伟 SUO Cheng-xiang;GUAN Meng-xue;WANG Feng;LIU Rui-bin;GUO Wei(School of Physics,Beijing Institute of Technology,Beijing 100081,China;Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement(MOE),Beijing Institute of Technology,Beijing 100081,China;Frontiers Science Center for High Energy Materials(MOS),Beijing Institute of Technology,Beijing 100081,China;State Key Laboratory of Explosion Mechanics,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北京理工大学物理学院,北京100081 [2]北京理工大学先进光电量子结构与测量重点实验室(MOS),北京100081 [3]北京理工大学高能量物质前沿科学中心,北京100081 [4]北京理工大学爆炸力学国家重点实验室,北京100081

出　　处：《火炸药学报》2023年第6期527-536,I0003,共11页Chinese Journal of Explosives & Propellants

基　　金：National Natural Science Foundation of China(NSFC,Grant No.51971037)。

摘　　要：采用含时密度泛函理论(TDDFT)计算了NTO、RDX、HMX、CL-20分子的光吸收谱、紫外光激发下分子的结构以及差分电荷密度随时间的演化。TDDFT模拟结果对比实验的感度趋势表明,在紫外光照下的激发态电子数目可作为分子水平上电子稳定性的描述符,其电子稳定性层级为NTO>CL-20>HMX>RDX。硝基脱离难易程度可作为分子水平上辐照感度的描述符,其感度层级为CL-20~RDX>HMX>NTO,NTO分子表现出最低的辐照感度。这4种火炸药分子在紫外光下发生的主要反应是脱氢、开环、硝基分离、硝基脱氧形成氮气,其中强吸电的硝基向周围转移电子起到了关键作用。不同光强诱导硝基上发生不同的电荷转移,产生不同的分解产物。模拟结果表明,光场较弱时硝基脱落形成二氧化氮,主要分解产物为二氧化氮、氢自由基。强光场下部分硝基脱氧形成亚硝基,若硝基解离能足够大,硝基可完全脱氧并脱离环状结构形成氮气,反应的中间产物包括氢、氧自由基、二氧化氮、亚硝基以及氮气分子。The time-dependent density functional theory(TDDFT)was used to study the light absorption spectra of 3-nitro-1,2,4-triazol-5-one(NTO),1,3,5-trinitroperhydro-1,3,5-triazine(RDX),1,3,5,7-tetranitrooctahydro-1,3,5,7-tetrazocine(HMX)and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo[5.5.0.0(3,11).0(5,9)]dodecane(CL-20)molecules,the evolution of molecular structure and differential charge density with time under Ultraviolet(UV)light.The sensitivity trends of TDDFT compared with the simulation results show that the number of excited-state electrons under UV light may serve as descriptors of electronic stability,where the electronic stability rank is NTO>CL-20>HMX>RDX.The ease of nitro group detachment under ultraviolet excitation may serve as descriptors of irradiation sensitivity in molecular level,where the irradiation sensitivity rank is CL-20—RDX>HMX>NTO.And NTO molecule exhibits the lowest irradiation sensitivity.Under UV light,these four explosive molecules undergo several main reactions,including dehydrogenation,ring opening,nitro group separation,and nitro group deoxygenation,to form nitrogen gas.The excited nitro group,known for its strong electron-withdrawing properties,plays a crucial role in electron transfer to the surrounding environment.The extent of charge transfer on the nitro group varies with light intensity,leading to the different decomposition products.The simulation results demonstrate that under weak light fields,nitro groups dissociate to form nitrogen dioxide,with the main decomposition products being nitrogen dioxide and hydrogen radicals.However,some nitro groups undergo deoxygenation to form nitrous groups when exposed to intense light.If the dissociation energy of the nitro group is sufficiently high,complete deoxygenation can occur,causing the nitro group to detach from the ring structure and form nitrogen.The intermediate products of the reaction include hydrogen,oxygen free radicals,nitrogen dioxide,nitroso,and nitrogen molecules.

关 键 词：量子化学 TDDFT 紫外光 火炸药分子 辐照感度 NTO RDX HMX CL-20 

分 类 号：TJ55[兵器科学与技术—军事化学与烟火技术] O64[理学—物理化学]