Department of Chemistry, University at Buffalo State University of New York, Buffalo, New York 14260-3000, USA.
Inorg Chem. 2011 Mar 7;50(5):1723-32. doi: 10.1021/ic102174b. Epub 2011 Jan 4.
The influences of solvent effects and dynamic averaging on the (195)Pt NMR shielding and chemical shifts of cisplatin and three cisplatin derivatives in aqueous solution were computed using explicit and implicit solvation models. Within the density functional theory framework, these simulations were carried out by combining ab initio molecular dynamics (aiMD) simulations for the phase space sampling with all-electron relativistic NMR shielding tensor calculations using the zeroth-order regular approximation. Structural analyses support the presence of a solvent-assisted "inverse" or "anionic" hydration previously observed in similar square-planar transition-metal complexes. Comparisons with computationally less demanding implicit solvent models show that error cancellation is ubiquitous when dealing with liquid-state NMR simulations. After aiMD averaging, the calculated chemical shifts for the four complexes are in good agreement with experiment, with relative deviations between theory and experiment of about 5% on average (1% of the Pt(II) chemical shift range).
采用显式和隐式溶剂化模型计算了溶剂效应和动态平均对顺铂和三种顺铂衍生物在水溶液中（195）Pt NMR 屏蔽和化学位移的影响。在密度泛函理论框架内，通过组合相空间采样的从头算分子动力学（aiMD）模拟和使用零阶正则近似的全电子相对论 NMR 屏蔽张量计算来进行这些模拟。结构分析支持了先前在类似的平面四方过渡金属配合物中观察到的溶剂辅助“反式”或“阴离子”水合作用的存在。与计算要求较低的隐式溶剂模型的比较表明，在处理液相 NMR 模拟时，误差消除是普遍存在的。经过 aiMD 平均后，计算得到的四个配合物的化学位移与实验值吻合较好，理论与实验之间的相对偏差平均约为 5%（Pt(II)化学位移范围的 1%）。
