Acta Phys. -Chim. Sin. ›› 2016, Vol. 32 ›› Issue (12): 2921-2931.doi: 10.3866/PKU.WHXB201609193

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Study on Coordination Microstructure andWater Exchange Reaction of Zn2+ Aqueous Solutions through Molecular Dynamics Simulations Using the ABEEMσπ Polarizable Force Field

Lan-Lan HE,Yu GUO,Jian ZHAO,Xin-Rui JIANG,Zhong-Zhi YANG*(),Dong-Xia ZHAO*()   

  • Received:2016-08-09 Published:2016-11-30
  • Contact: Zhong-Zhi YANG,Dong-Xia ZHAO E-mail:zzyang@lnnu.edu.cn;zhaodxchem@lnnu.edu.cn
  • Supported by:
    The project was supported by the National Natural Science Foundation of China(21133005,21473083);General Project of Education Department ofLiaoning Province, China(L2014426);and Laboratory Opening Program of Liaoning Normal University, China(cx20160111)

Abstract:

Coordination microstructure and water exchange of Zn2+ aqueous solution were studied through molecular dynamics simulations based on the ABEEMσπ polarizable force field with the precise ABEEM-7P model. Structural and dynamical properties were investigated in detail. We show that the first-shell water coordination number is six, which is in agreement with the experimental value. During the water exchange process, H2O, which attacks or leaves the first solvation shell of Zn2+, is orientated on the upper or lower inclined side of the ∠O-Zn-O bisector. The distance change between Zn2+ and the oxygen atom of the exchange water for the polarizable force field fluctuates more than that observed for the fixed charge force field. The radial distribution function (RDF) of the polarizable force field showed clearly the microstructure of the second and third solvation shells. The subshell of the second solvation shell was found to exchange with the first solvation shell. The polarizable effect of Zn2+ has been fully expressed. The charges of the Zn2+ site and the lone-pair sites in exchange water regularly change, demonstrating the rationality of water exchange. The mean ligand residence time (2.0×10-9 s) of the first-shell water produced by the ABEEMσπ polarizable force field is within the range of the experimental value. Zn2+ aqueous solution can be reasonably simulated through the ABEEMσπ polarizable force field.

Key words: ABEEMσπ polarizable force field, Molecular dynamic simulation, Water exchange reaction, Radial distribution function, Charge analysis, Mean ligand residence time

MSC2000: 

  • O641