分子间氢键与氢转移对炸药感度的影响研究

Safety is one of the most concerned properties of explosives, whose indicator is usually sensitivity. Because the sensitivity is determined by multiscale and hierarchical structures, external stimuli, and so forth, it has already become one of the most complicated scientific issues in the field of explosives. Hydrogen-contained explosives are most extensively applied and occupy a large population in designed explosives. Hydrogen bonds and hydrogen transfer occur generally in hydrogen-contained explosives and dominate some their structures and properties essentially. They also are the key points for exploring the sensitivity mechanics. The molecular simulations, the method for fingerprinting the intermolecular interactions in molecular crystals and other theories and experimental methods involved in the explosive subject will be employed to carry out the following investigations: the influence of hydrogen bonds on the impact senstivities of explosives in terms of a path of hydrogen bonds in crystals to molecular stacking, shear features of crystals and impact sensitivity; the mechanism of hydrogen transfer in thermal reactions and its influence on thermal sensitivity of condensed explosives (crystals); the reversible proton transfer in energetic salt TKX-50; and the regularities of these influences (possibly, we will find novel impact sensitivity mechanism of the energy dissipation by a reversible chemical reaction). The work is hopefully to be useful to deep understand the sensitivity mechanism, richen the structure-property relationships and design new kinds of explosives.

安全性在炸药研究中倍受关注，通常以感度度量。感度受炸药多尺度多层次结构和外界刺激条件等多种因素的影响，是炸药领域中最复杂的科学问题之一。含氢炸药是当前应用最多的单体炸药，也是设计新型混合炸药的主要能量组分。氢键与氢转移普遍存在于含氢炸药中，是决定其结构与性能的本质因素之一，因此可作为研究其感度机制的重要切入点。本项目拟采用分子模拟方法、分子晶体中分子间相互作用指纹方法及炸药相关理论与实验方法，以“晶体中的氢键→分子堆积特性→晶体的剪切特性→撞击感度”脉络研究炸药中氢键对撞击感度的影响；其次研究其凝聚态体系在热反应条件下氢转移机制，以探索氢转移对热感度的影响；最后研究高能离子盐TKX-50在低热条件下的可逆的质子转移机制，进而揭示氢键与氢转移对感度影响规律，可能会发现一种全新的通过可逆化学反应耗散能量的撞击感度机制。本研究将有助于深刻认知炸药感度机制、丰富炸药结构-性能关系及设计新型炸药。

安全性是炸药最重要的两个特征之一，常以感度标度，是炸药研究领域中的重点和难点。本项目以氢键和氢转移为切入点，研究了它们对炸药结构、性能，特别是感度的影响，获得了如下结果：（1）全面总结了含能晶体中分子间作用（含氢键与π-π作用）特点，揭示了其对撞击感度的影响规律，并从晶体工程的角度提出了构造低感高能晶体的策略。（2）系统研究了含能分子晶体与离子晶体中的氢转移反应，发现了一种基于可逆氢转移的低感机制及含能化合物自发分解并非“一触即发”。（3）发现了一种罕见的羟胺阳离子的质子化现象，揭示了强酸性、质子化能力及分子稳定性是决定含能离子盐热稳定性的根本要素，诠释了含能离子盐热稳定性的本质。本研究具有以下意义：丰富了炸药感度机制，特别是氢原子在结构演变过程与分解反应中所起的作用；深化了炸药结构-性能关系认知，特别是氢键对晶格中分子堆积、晶体力学特性、撞击感度的影响规律和氢转移对热感度和撞击感度的影响规律。这些结果为实现新型低感高能炸药的晶体工程提供了策略。