标题： 关于液态过氧化氢中手性对称性破缺的可能性 显示英文标题

标题： On the possibility of chiral symmetry breaking in liquid hydrogen peroxide

摘要： 分子手性是化学中的一个关键概念，与生命的起源以及制药业的制造密切相关。先前对一个具有向同手性相互作用能量偏向的手性分子模型的模拟显示，在超临界外消旋液体和亚临界液体（富集两种对映体之一）之间的自发对称性破缺转变。在这里，我们采用分子动力学模拟来测试这种现象是否可能在过氧化氢（最小的手性分子）中存在。为此，我们在100 K到1500 K之间以及从 $10^{-4}$ GPa 到 1 GPa 的压力范围内研究了该物质的流体相。我们发现了一个玻璃化转变，并建议氢键在这种行为中起着核心作用。我们还通过在多个压力下进行恒温模拟和冷却模拟来测试观察手性对称性破缺的可能性，但并未观测到这一现象。对液体结构的分析表明同手性和异手性相互作用之间几乎没有差异，这支持了观测手性对称性破缺的困难性。如果过氧化氢表现出自发的手性对称性破缺，那么它很可能发生在远低于室温的条件下，并被其他现象（如玻璃化转变或结晶）所掩盖。更广泛地说，我们的结果和最近的实验观察表明，在液体相中发生自发手性对称性破缺需要更高的分子复杂性。 显示英文摘要

摘要： Molecular chirality is a key concept in chemistry with implications for the origin of life and the manufacturing of pharmaceuticals. Previous simulations of a chiral molecular model with an energetic bias towards homochiral interactions show a spontaneous symmetry-breaking transition from a supercritical racemic liquid into a subcritical liquid enriched in one of the two enantiomers. Here, we employ molecular dynamics simulations in order to test the possible existence of this phenomenon in hydrogen peroxide, the smallest chiral molecule. For this purpose, we study the fluid phase of this substance between 100 K and 1500 K, and from $10^{-4}$ GPa to 1 GPa. We find a glass transition and we suggest that hydrogen bonds play a central role in such behavior. We also test the possibility of observing chiral symmetry breaking by performing both constant temperature and cooling simulations at multiple pressures, and we do not observe the phenomenon. An analysis of the structure of the liquid shows negligible differences between homochiral and heterochiral interactions, supporting the difficulty in observing chiral symmetry breaking. If hydrogen peroxide manifests spontaneous chiral symmetry breaking, it likely takes place significantly below room temperature and is hidden by other phenomena, such as the glass transition or crystallization. More broadly, our results, and recent experimental observations, suggest that greater molecular complexity is needed for spontaneous chiral symmetry breaking in the liquid phase to occur.