Assessing the Impact of Tagging Species on the Fluxional Behavior of Protonated Methane

评估标记物种对质子化甲烷通量行为的影响

• 批准号: 409795857
• 负责人: Professor Dr. Dominik Marx
• 金额: --
• 依托单位: Lehrstuhl für Theoretische Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/409795857?language=en
• 关键词: Assessing; Impact; Tagging; Species; Fluxional

Protonated methane is considered to be an archetypal fluxional molecule since pronounced large-amplitude motion leads to so-called hydrogen scrambling. Given the fundamental importance of this parent of non-classical carbocations, it has been intensely studied since decades. What remains essentially unexplored, however, are the putative interaction-induced perturbations of large-amplitude motion and scrambling due to attaching weakly interacting light species, which is the exclusive focus of this project. Indeed, protonated methane has been tagged using hydrogen molecules in pioneering messenger action spectroscopy work of Y. T. Lee. Moreover, helium atoms are another ideal tagging species that has been widely used for other molecules, in particular quasi-rigid ones. This project has two different components which are enabled by using two distinct ab initio path integral-based techniques as developed recently. The first focus is the approximate computation of broadband infrared spectra at temperatures on the order of 100 K down to the region of low frequencies to elucidate the interactions of protonated methane with a few hydrogen molecules in terms of vibrational spectroscopy. The second focus is on the impact of only a few helium-four atoms in conjunction with Bose-Einstein statistics on large-amplitude motion and scrambling of protonated methane at temperatures on the order of 1 K in terms of its molecular structure.

质子化甲烷被认为是一个典型的流动分子，因为明显的大幅度运动导致所谓的氢混乱。鉴于这种非经典碳正离子的母体的根本重要性，几十年来一直在进行深入研究。然而，基本上尚未探索的是假定的相互作用引起的大幅度运动扰动和由于附着弱相互作用光物种而引起的混乱，这是该项目的唯一焦点。事实上，质子化甲烷已被标记使用氢分子在先驱信使行动光谱工作的Y。T.李你此外，氦原子是另一种理想的标记物种，已被广泛用于其他分子，特别是准刚性分子。这个项目有两个不同的组件，这是通过使用两个不同的从头算路径积分为基础的技术，最近开发的。第一个重点是近似计算的宽带红外光谱在温度上的顺序为100 K下降到该地区的低频率，以阐明质子化甲烷与一些氢分子的相互作用的振动光谱。第二个重点是只有几个氦-四原子的影响，结合玻色-爱因斯坦统计的大幅度运动和混乱的质子化甲烷的温度在1 K的顺序在其分子结构。