Experimental and TD-DFT Study of Optical Absorption of Six Explosive Molecules: RDX, HMX, PETN, TNT, TATP, and HMTD
Experimental and TD-DFT Study of Optical Absorption of Six Explosive Molecules: RDX, HMX, PETN, TNT, TATP, and HMTD
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DOI：
10.1021/jp312492v
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发表时间：
2013-07-25
影响因子：
2.9
通讯作者：
Zhang, Jin Z.
中科院分区：
文献类型：
--
作者：
Cooper, Jason K.;Grant, Christian D.;Zhang, Jin Z.
时间相关密度函数理论（TD-DFT）已用于计算六种常见炸药的激发能和振荡器强度：RDX（1,3,5-三硝基过氢-1,3,5-三嗪）、β-HMX（八氢-1,3,5,7-四硝基-1,3,5,7-四佐辛）、TATP（三过氧化三丙酮）、HMTD（六亚甲基三过氧化二胺）、 TNT（2,4,6-三硝基甲苯）和PETN（季戊四醇四硝酸酯）。将结果与在乙腈中收集的实验紫外-可见吸收光谱进行比较。测试了四种计算方法，包括：B3LYP、CAM-B3LYP、omega B97XD 和 PBE0。 PBE0 优于其他测试方法。使用 6-31G(d)、6-31+G(d)、6-31+G(d,p) 和 6-311+G(d,p) 评估基组对电子能量和振荡器强度的影响。所需的最小基组为 6-31+G(d)；然而，使用 6-311+G(d,p) 进行了额外的计算。对于所研究的每个分子，报告了最突出的单线态激发的自然过渡轨道（NTO）。 TD-DFT 结果与 CBS-QB3 计算的 IPv 相结合，构建了六种化合物的能级图。结果通过指导材料选择以实现荧光探针和爆炸物分析物之间的最佳谱带对准，提出了针对这些爆炸物的基于荧光的检测方法的优化方法。此外，还讨论了 TNT Meisenheimer 络合物的形成及其所得电子结构对 II-VI 族半导体猝灭机制的作用。
Time dependent density function theory (TD-DFT) has been utilized to calculate the excitation energies and oscillator strengths of six common explosives: RDX (1,3,5-trinitroperhydro-1,3,5-triazine), beta-HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine), TATP (triacetone triperoxide), HMTD (hexamethylene triperoxide diamine), TNT (2,4,6-trinitrotoluene), and PETN (pentaerythritol tetranitrate). The results were compared to experimental UV-vis absorption spectra collected in acetonitrile. Four computational methods were tested including: B3LYP, CAM-B3LYP, omega B97XD, and PBE0. PBE0 outperforms the other methods tested. Basis set effects on the electronic energies and oscillator strengths were evaluated with 6-31G(d), 6-31+G(d), 6-31+G(d,p), and 6-311+G(d,p). The minimal basis set required was 6-31+G(d); however, additional calculations were performed with 6-311+G(d,p). For each molecule studied, the natural transition orbitals (NTOs) were reported for the most prominent singlet excitations. The TD-DFT results have been combined with the IPv calculated by CBS-QB3 to construct energy level diagrams for the six compounds. The results suggest optimization approaches for fluorescence based detection methods for these explosives by guiding materials selections for optimal band alignment between fluorescent probe and explosive analyte. Also, the role of the TNT Meisenheimer complex formation and the resulting electronic structure thereof on of the quenching mechanism of II-VI semiconductors is discussed.