Perturbation of Local Solvent Structure by a Small Dication: A Theoretical Study on Structural, Vibrational, and Reactive Properties of Beryllium Ion in Water

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• 作者：S. Gnanakaran ; Brian Scott ; T. Mark McCleskey ; Angel E. Garcia
• 刊名：Journal of Physical Chemistry B
• 出版年：2008
• 出版时间：March 13, 2008
• 年：2008
• 卷：112
• 期：10
• 页码：2958 - 2963
• 全文大小：250K
• 年卷期：v.112,no.10(March 13, 2008)
• ISSN：1520-5207

文摘

A molecular based understanding of beryllium chemistry in the context of biomolecules is necessary forgaining progress in prevention and treatment of chronic beryllium disease. One aspect that has hindered thetheoretical progress has been the lack of a simple classical two-body potential for the aqueous beryllium ion(Be²⁺) to be used with biomolecular simulations. We provide new parameters for Be²⁺ that capture the structuraland reactive properties of this small dication. Using classical molecular dynamics simulations, we show thatthese parameters reproduce the correct radial distribution function and coordination numbers for this cationin explicit aqueous solution when compared to published diffraction and NMR measurements. The geometricalparameters obtained using classical simulations are also in agreement with ab initio calculations. We successfullypredict the vibrational modes of the tetra aqua Be²⁺ dication from ab initio calculations on solvated structuresobtained from the simulations. The calculated vibrational modes show better agreement with experimentscompared to any published work. This new potential also produces a well-established hydrogen bondingbetween the first and second solvation shells. More importantly, when the molecular dynamics (MD) and abinitio results are interpreted in concert, the dynamics and nature of interactions between the first and secondshells capture the pivotal role they play on the reactivity of aqua-Be complexes.