Proton exchange of carbonic acid and methylamine complex accelerated by a single-water molecule via intermolecular hydrogen bonding: A theoretical investigation

A theoretical investigation of the microsolvation effect on proton exchange (PE) between carbonic acid and methylamine (CA-MTA) has been explored by quantum dynamics simulations. The structural, energy, and dynamic properties of the CA-MTA complex with and without an explicit water molecule are eluc...

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Bibliographic Details
Published in:Chemical Physics Impact
Main Authors: Pakuna Panbo, Apirak Payaka, Rusrina Salaeh, Rathawat Daengngern
Format: Article in Journal/Newspaper
Language:English
Published: Elsevier 2024
Subjects:
Online Access:https://doi.org/10.1016/j.chphi.2023.100451
https://doaj.org/article/9f719490cd5b411ca4e6899cd11ab305
Description
Summary:A theoretical investigation of the microsolvation effect on proton exchange (PE) between carbonic acid and methylamine (CA-MTA) has been explored by quantum dynamics simulations. The structural, energy, and dynamic properties of the CA-MTA complex with and without an explicit water molecule are elucidated at the molecular level. The reactions from this study have been clarified into different types: single-step PE (SSPE) and stepwise PE (SWPE). Without the water molecule, the SSPE mechanism is hardly found but observable with a low probability of 0.2. In particular, the water molecule interacting through intermolecular hydrogen-bonded network between CA and MTA in CA-MTA-Win could affect PE by showing both SSPE and SWPE mechanisms. In addition, the existing water molecule plays the significant role in shortening intermolecular hydrogen bonding interactions within the complex resulting in increasing the probability of PE up to 0.92 especially in CA-MTA-Wout. Hence, one water molecule could be used to provide reliable results to represent the significant activity that occurs for the proton exchangeability of the CA and MTA complex.