Photoreactions Create Superconducting Materials
Photoreactions Create Superconducting Materials
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DOI：
10.1007/s10812-023-01577-9
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发表时间：
2023-06
影响因子：
0.7
通讯作者：
Yulun Han;D. Kilin
中科院分区：
文献类型：
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作者：
Yulun Han;D. Kilin
科学发展的潜在变革领域之一是在室温下实现超导。近年来，人们利用光化学合成法制备了具有室温超导性的碳质硫氢化物（CSH）体系。在这项工作中，我们提出了一个第一性原理的研究，旨在解开硫与分子氢的光反应，使用含时激发态分子动力学（TDESMD）的方法。单个TDESMD轨迹提供了有关导致硫的许多同素异形体及其氢化形式的反应的详细信息。基于TDESMD轨迹系综的模拟质谱提供了硫烷沿着反应途径的分布。研究发现，光化学反应是从环S8的开环开始的，环S8与两个H自由基反应生成S8H2，这是H2均裂解离的结果.硫簇将经历小碎片的消除，这些小碎片随后可以重组成各种硫烷。沿沿着轨迹产生的最丰富的碎片是H2S、S4H2和S8H2。最终的含硫产物是具有各种链和环的硫烷的混合物。从这项工作中获得的机械和构象信息，使我们能够更好地理解的光反应，并可能，给洞察到使用类似的反应物制备高Tc材料。
One of the potentially transformative areas of scientific development is to achieve superconductivity at room temperature. Recently, the photochemical synthesis was carried out to prepare carbonaceous sulfur hydride (CSH) systems with room-temperature superconductivity at high pressure. In this work, we present a first-principles study aiming to unravel the photoreaction of sulfur with molecular hydrogen using the time-dependent excited-state molecular dynamics (TDESMD) methodology. Individual TDESMD trajectory provides details about reactions that lead to a number of allotropes of sulfur and their hydrogenated forms. Simulated mass spectra based on an ensemble of TDESMD trajectories provide the distribution of sulfanes along reaction pathways. It is found that the photoreaction starts with ring opening of cyclic S8, which may then react with two H radicals to form S8H2as a result of the homolytic dissociation of H2. The sulfur cluster will undergo the elimination of small fragments, which can later recombine into a variety of sulfanes. The most abundant fragments generated along trajectories are H2S, S4H2, and S8H2. The final sulfur-bearing products are a mixture of sulfanes with various chains and rings. The mechanistic and conformational information obtained from this work allows us to better understand the photoreaction, and potentially, give insights into the preparation of high Tcmaterials using similar reactants.