Collective Proton Tunneling in Ice?

冰中集体质子隧道？

• 批准号: 238570623
• 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: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/238570623?language=en
• 关键词: Collective; Proton; Tunneling; Ice

Proton transfer in hydrogen-bonded networks plays an important role in many chemical, biological, and industrial processes. Although quantum effects on proton transfer involving a single proton or two protons are well investigated by simulation they remain elusive when it comes to many-body concerted proton motion triggered by collective motion. Recent experiments have provided evidence that concerted tunneling involving as many as six protons might underly the non-Arrhenius proton dynamics observed at low temperatures in ordinary hexagonal ice - yet any mechanistic explanations are lacking beyond speculations. In this project ab initio path integral simulations will be used to investigate the mechanism of the alleged concerted tunneling of six protons in hexagonal ice. Here, quantum effects are qualitatively important to understand the phenomenon, and do not only broaden distribution functions and lower free energy barriers as usually found as a "trivial" consequence of small-amplitude zero-point vibrations. It is thus expected that the mechanistic insights gained into collective proton tunneling will be of broad importance beyond the specific case.

氢键网络中的质子转移在许多化学、生物和工业过程中起着重要作用。虽然量子效应对单个或两个质子的质子转移的模拟研究很好，但当涉及到由集体运动触发的多体协调质子运动时，它们仍然难以捉摸。最近的实验提供了证据，表明在普通六边形冰中，在低温下观察到的非阿伦尼乌斯质子动力学可能包含多达6个质子的协同隧道作用，但除了猜测之外，还缺乏任何机制解释。在这个项目中，从头算路径积分模拟将用于研究所谓的六质子在六边形冰中协同隧穿的机制。在这里，量子效应对于理解这一现象具有重要的定性意义，它不仅拓宽了分布函数，降低了自由能垒，而这通常是小振幅零点振动的“微不足道”结果。因此，预期对集体质子隧穿所获得的机制见解将具有超越具体情况的广泛重要性。

项目成果

Protons in concert

• DOI: 10.1038/nphys3269
• 发表时间: 2015-02
• 期刊: Nature Physics
• 影响因子: 19.6
• 作者: C. Drechsel-Grau;D. Marx

Quantum simulation of collective proton tunneling in hexagonal ice crystals.

• DOI: 10.1103/physrevlett.112.148302
• 发表时间: 2014-04
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: C. Drechsel-Grau;D. Marx

Collective proton transfer in ordinary ice: local environments, temperature dependence and deuteration effects.

• DOI: 10.1039/c6cp05679b
• 发表时间: 2017-01
• 期刊: Physical chemistry chemical physics : PCCP
• 作者: C. Drechsel-Grau;D. Marx