Sakti Aditya Wibawa, Nishimura Yoshifumi, Nakai Hiromi
Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University , Tokyo 169-8555, Japan.
Research Institute for Science and Engineering, Waseda University , Tokyo 169-8555, Japan.
J Chem Theory Comput. 2018 Jan 9;14(1):351-356. doi: 10.1021/acs.jctc.7b00855. Epub 2017 Dec 21.
Predicting pK 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 pK values were in satisfactory agreement with the experimental values, the mean absolute deviation being only 0.09 pK units for 34 amines commonly used in CO 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.
高精度、高效率地预测不同类型胺类物质的pK值对于设计用于胺水溶液碳捕获与封存的高性能且经济的溶剂至关重要。在本研究中，我们证明基于密度泛函紧束缚的元动力学模拟是一种以低廉计算成本计算胺在水溶液中质子化态与中性态之间自由能差的有前景的方法。计算得到的pK值与实验值吻合良好，对于常用于CO洗涤的34种胺，平均绝对偏差仅为0.09 pK单位。与静态量子力学计算的估计值相比，这种卓越的重现性和相关性突出了明确溶剂分子中动态质子转移过程对提高估计精度的显著影响。
