Lease Nicholas, Cawkwell M J, Spielvogel Kyle D, Manner Virginia W
High Explosives Science and Technology, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
J Phys Chem Lett. 2025 Jan 16;16(2):579-586. doi: 10.1021/acs.jpclett.4c03306. Epub 2025 Jan 7.
The ability to predict the handling sensitivity of new organic energetic materials has been a longstanding goal. We report the synthesis and characterization of six new nitropicramide energetic materials with mixed functional groups that mimic known explosives such as nitroglycerin, erythritol tetranitrate (ETN), and pentaerythritol tetranitrate (PETN). The molecules have been studied theoretically using quantum molecular dynamics (QMD) simulations and density functional theory (DFT) calculations to identify the weakest bond in the reactants - the trigger-linkages - which control handling sensitivity, and to quantify their specific enthalpies of explosion. In good accord with the drop weight impact sensitivity data, our calculations predict that the sensitivities of the molecules are very similar owing to the small variations of the energy output and rates of trigger linkage rupture. In addition, both the QMD and DFT calculations point to the nitropicramide N-NO bonds as the trigger linkages rather than the more typical O-NO bonds. We propose that the switch of the trigger linkage from the nitrate esters to the nitramine groups arises from the strongly electron withdrawing character of the adjacent trinitrobenzene groups.
预测新型有机含能材料的操作灵敏度一直是一个长期目标。我们报告了六种具有混合官能团的新型硝呋酰胺含能材料的合成与表征，这些材料模拟了已知炸药，如硝化甘油、四硝酸赤藓醇（ETN）和季戊四醇四硝酸酯（PETN）。已使用量子分子动力学（QMD）模拟和密度泛函理论（DFT）计算对这些分子进行了理论研究，以确定反应物中最弱的键——触发键——它控制着操作灵敏度，并量化它们的比爆炸焓。与落锤冲击灵敏度数据高度一致，我们的计算预测，由于能量输出和触发键断裂速率的微小变化，这些分子的灵敏度非常相似。此外，QMD和DFT计算均表明硝呋酰胺的N-NO键是触发键，而非更典型的O-NO键。我们认为，触发键从硝酸酯基团转变为硝胺基团是由于相邻三硝基苯基团的强吸电子特性。
