TY - JOUR
T1 - Rigorous pKa Estimation of Amine Species Using Density-Functional Tight-Binding-Based Metadynamics Simulations
AU - Sakti, Aditya Wibawa
AU - Nishimura, Yoshifumi
AU - Nakai, Hiromi
N1 - Funding Information:
This study was supported in part by a Grant-in-Aid for Scientific Research (A) “KAKENHI Grant Number JP26248009” from the Japan Society for the Promotion of Science (JSPS), a Grand-in-Aid for Challenging and Exploratory Research “KAKENHI 15K13629” from the Ministry of Education, Culture, Sports, Science, and Technology (MEXT), Japan, and by MEXT as “Priority Issue on Post-K computer” (Development of new fundamental technologies for high-efficiency energy creation, conversion/storage, and use). One of the authors (A.W.S.) acknowledges financial support from the Yoshida Scholarship Foundation (YSF). Some of the calculations were performed at the Research Center for Computational Science (RCCS), Okazaki, Japan.
Publisher Copyright:
© 2017 American Chemical Society.
PY - 2018/1/9
Y1 - 2018/1/9
N2 - Predicting pKa values for different types of amine species with high accuracy and efficiency is of critical importance for the design of high performance and economical solvents in carbon capture and storage with aqueous amine solutions. In this study, we demonstrate that density-functional tight-binding-based metadynamics simulations are a promising approach to calculate the free energy difference between the protonated and neutral states of amines in aqueous solution with inexpensive computational cost. The calculated pKa values were in satisfactory agreement with the experimental values, the mean absolute deviation being only 0.09 pKa units for 34 amines commonly used in CO2 scrubbing. Such superior reproducibility and correlation compared to estimations by static quantum mechanical calculations highlight the significant effect of dynamical proton transfer processes in explicit solvent molecules for the improvement of the estimation accuracy.
AB - Predicting pKa values for different types of amine species with high accuracy and efficiency is of critical importance for the design of high performance and economical solvents in carbon capture and storage with aqueous amine solutions. In this study, we demonstrate that density-functional tight-binding-based metadynamics simulations are a promising approach to calculate the free energy difference between the protonated and neutral states of amines in aqueous solution with inexpensive computational cost. The calculated pKa values were in satisfactory agreement with the experimental values, the mean absolute deviation being only 0.09 pKa units for 34 amines commonly used in CO2 scrubbing. Such superior reproducibility and correlation compared to estimations by static quantum mechanical calculations highlight the significant effect of dynamical proton transfer processes in explicit solvent molecules for the improvement of the estimation accuracy.
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U2 - 10.1021/acs.jctc.7b00855
DO - 10.1021/acs.jctc.7b00855
M3 - Article
C2 - 29206463
AN - SCOPUS:85040373880
SN - 1549-9618
VL - 14
SP - 351
EP - 356
JO - Journal of chemical theory and computation
JF - Journal of chemical theory and computation
IS - 1
ER -