文献类型：期刊文献

英文题名：Hydrated cation-π interactions of π-electrons with hydrated Mg2+ and Ca2+ cations

作者：Mu, Liuhua[1,2];Shi, Guosheng[1,3];Fang, Haiping[4]

机构：[1]Univ Chinese Acad Sci, Wenzhou Inst, Wenzhou 325001, Zhejiang, Peoples R China;[2]Univ Chinese Acad Sci, Sch Phys Sci, Beijing 100049, Peoples R China;[3]Shanghai Univ, Shanghai Appl Radiat Inst, State Key Lab Adv Special Steel, Shanghai 201800, Peoples R China;[4]East China Univ Sci & Technol, Sch Phys, Shanghai 200237, Peoples R China

年份：2024

卷号：160

期号：21

外文期刊名：JOURNAL OF CHEMICAL PHYSICS

收录：;EI(收录号：20242416233658);WOS:【SCI-EXPANDED(收录号:WOS:001242309400006)】；

基金：This work was supported by the National Natural Science Foundation of China (Grant Nos. 11974366 and U1932123), the National Science Fund for Outstanding Young Scholars (Grant No. 11722548), the Postdoctoral Fellowship Program of CPSF (Grant No. GZC20232610), and the Fundamental Research Funds for the Central Universities. The authors thanked the Shanghai Supercomputer Center for computing time.

语种：英文

外文关键词：Alkaline earth metals - Alkalinity - Aromatic compounds - Density functional theory - Hydration - Molecules - Phase interfaces - Positive ions

摘要：Hydrated cation-pi interactions at liquid-solid interfaces between hydrated cations and aromatic ring structures of carbon-based materials are pivotal in many material, biological, and chemical processes, and water serves as a crucial mediator in these interactions. However, a full understanding of the hydrated cation-pi interactions between hydrated alkaline earth cations and aromatic ring structures, such as graphene remains elusive. Here, we present a molecular picture of hydrated cation-pi interactions for Mg2+ and Ca2+ by using the density functional theory methods. Theoretical results show that the graphene sheet can distort the hydration shell of the hydrated Ca2+ to interact with Ca2+ directly, which is water-cation-pi interactions. In contrast, the hydration shell of the hydrated Mg2+ is quite stable and the graphene sheet interacts with Mg2+ indirectly, mediated by water molecules, which is the cation-water-pi interactions. These results lead to the anomalous order of adsorption energies for these alkaline earth cations, with hydrated Mg2+-pi < hydrated Ca2+-pi when the number of water molecules is large (n >= 6), contrary to the order observed for cation-pi interactions in the absence of water molecules (n = 0). The behavior of hydrated alkaline earth cations adsorbed on a graphene surface is mainly attributed to the competition between the cation-pi interactions and hydration effects. These findings provide valuable details of the structures and the adsorption energy of hydrated alkaline earth cations adsorbed onto the graphene surface.