Theoretical investigation of the dissociative interchange (Id) mechanism for water exchange on magnesium(II) in aqueous solution
Theoretical investigation of the dissociative interchange (Id) mechanism for water exchange on magnesium(II) in aqueous solution
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DOI：
10.1016/j.ica.2010.06.042
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发表时间：
2010-10-25
影响因子：
2.8
通讯作者：
Chen, Jianrong
中科院分区：
文献类型：
--
作者：
Qian, Zhaosheng;Feng, Hui;Chen, Jianrong
A dissociative (D) and a solvent-assisted dissociative interchange (I-d) water-exchange pathways for magnesium( II) in aqueous solution were simulated with density functional theory calculations. The D mechanism of Mg(H2O)(6)(2+) includes a five-coordinated intermediate, while the I-d water-exchange pathway of Mg(H2O)(6)(2+) proceeds with the assistance of a solvent water molecule, which supports the experimental assignment of the reaction mechanism. The intrinsic activation volume was used to differentiate between I-d and I-a mechanisms despite of the exclusion of the contribution of transmission coefficient. The calculated intrinsic activation volume for the I-d mechanism is consistent with the experimental data, and is closer to the experimental data than that for D mechanism. The I-d mechanism is suggested as the dominate water-exchange pathway of Mgd(H2O)(6)(2+) depending on the intrinsic activation volume with the assistance of the activation entropy. The calculations also showed that the influences of the explicit and bulk waters on energy barriers for D and I-d mechanisms are obviously different. (C) 2010 Elsevier B.V. All rights reserved.
