Upadhyay Meenu, Meuwly Markus
Department of Chemistry, University of Basel, Basel, Switzerland.
Front Chem. 2022 Feb 8;9:827085. doi: 10.3389/fchem.2021.827085. eCollection 2021.
The formation of molecules in and on amorphous solid water (ASW) as it occurs in interstellar space releases appreciable amounts of energy that need to be dissipated to the environment. Here, energy transfer between CO formed within and on the surface of amorphous solid water (ASW) and the surrounding water is studied. Following CO(Σ) + O(D) recombination the average translational and internal energy of the water molecules increases on the ps time scale by 15-25% depending on whether the reaction takes place on the surface or in an internal cavity of ASW. Due to tight coupling between CO and the surrounding water molecules the internal energy exhibits a peak at early times which is present for recombination on the surface but absent for the process inside ASW. Energy transfer to the water molecules is characterized by a rapid ps and a considerably slower ns component. Within 50 ps a mostly uniform temperature increase of the ASW across the entire surface is found. The results suggest that energy transfer between a molecule formed on and within ASW is efficient and helps to stabilize the reaction products generated.
在星际空间中，非晶态固态水（ASW）内部及表面分子的形成会释放出可观的能量，这些能量需要耗散到周围环境中。在此，研究了在非晶态固态水（ASW）内部及表面形成的一氧化碳（CO）与周围水分子之间的能量转移。在CO(Σ) + O(D)复合之后，水分子的平均平动能量和内能在皮秒时间尺度上增加了15% - 25%，这取决于反应发生在ASW的表面还是内部腔体中。由于CO与周围水分子之间的紧密耦合，内能在早期呈现出一个峰值，该峰值出现在表面复合过程中，但在ASW内部的过程中不存在。能量转移到水分子的过程具有一个快速的皮秒分量和一个相当缓慢的纳秒分量。在50皮秒内，发现整个ASW表面的温度有大致均匀的升高。结果表明，在ASW内部及表面形成的分子之间的能量转移是有效的，有助于稳定所产生的反应产物。
