Asymmetric hydrogen bonding in formic acid–nitric acid dimer observed by quantum molecular dynamics simulations

详细信息    查看全文

• 作者：Chanisorn Ngaojampa ; Tsutomu Kawatsu ; Yuki Oba…
• 关键词：Formic acid–nitric acid dimer ; Path integral molecular dynamics simulation ; Nuclear quantum effect ; Isotopic effect ; Hydrogen bond
• 刊名：Theoretical Chemistry Accounts
• 出版年：2017
• 出版时间：March 2017
• 年：2017
• 卷：136
• 期：3
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Theoretical and Computational Chemistry; Inorganic Chemistry; Organic Chemistry; Physical Chemistry; Atomic/Molecular Structure and Spectra;
• 出版者：Springer Berlin Heidelberg
• ISSN：1432-2234
• 卷排序：136

文摘

Heterodimer of formic acid and nitric acid, of which the monomer acidity has large difference, was studied by on-the-fly ab initio molecular dynamics (AIMD) and path integral molecular dynamics (PIMD) simulations with RI-BVWN/SVP level of density functional theory, to elucidate the nuclear quantum effect and isotopic effect on the structural dynamics of the heterodimer. At 300 K, the two hydrogen bonds were maintained in both AIMD and PIMD regimes. Analyses in structural parameters suggested that this heterodimer should exist in the asymmetric binding mode, where hydrogen bonding is stronger on the C=O…H–O–N side. The asymmetry in the binding can be observed even more when the nuclear quantum effect was introduced. Although the complex has an equal conformation connected by a double hydrogen bonding, analyses in the principal component modes revealed the dominance of the dimer opening and twisting motions, which were suggested to obstruct double-proton transfer.