Molecular dynamics simulation for DMA aqueous solution
ZHU Long-hua, SHEN Xiao-chun, PING Lei, WANG Lan-zhou (College of Life Sciences, China Jiliang University, Hangzhou 310018, China)
The optimized Potentials for Liquid Simulations-All Atom (OPLSAA) model has been used in molecular dynamics simulation for N, N-dimethylacetamide (DMA) aqueous solutions at 298.15 K. The radial distribution functions of solutions were determined. Proportion fractions of various types of hydrogen at different DMA concentration were counted and the corresponding ~1H NMR data were fitted. Good agreements were obtained when these calculated values were compared with experimental values. The simulation results show that the OPLSAA model is reliable and can reflect the essence potential energy of DMA aqueous solutions. In addition, these results were compared with those of aqueous N, N-dimethyformamide (DMF) solutions. It was found that the hydrogen bond interaction of DMA and H_2O was stronger than that of DMF. The effect of the amides on the structure of water was very mach dependent upon the solution composition and the intrinsic molecular structure of the amides.