Lynden-Bell R M
Department of Chemistry, University of Cambridge, Cambridge, United Kingdom.
J Chem Phys. 2008 Nov 28;129(20):204503. doi: 10.1063/1.3020439.
Simulations of a model ionic liquid, [dmim][PF(6)] (dimethylimidazolium hexafluorophosphate), containing solute ions of different sizes and shapes have been used to investigate the changes in redox potentials of and screening around solute ions of different sizes and shapes. The effective solute size of spherical ions increases with the actual solute size although more slowly than expected. The effective solute size of tetrahedral or square planar ions varies little with actual ligand size. These results are clarified by reference to the charge density in the solvent around the ions, which is also used to calculate the potential within the solvent. Screening is essentially complete within 1 nm of the solute ion although charge density oscillations propagate further into the liquid. The results are compared to theoretical models and the implications for experiments are discussed.
对含有不同尺寸和形状溶质离子的模型离子液体[dmim][PF(6)]（二甲基咪唑鎓六氟磷酸盐）进行了模拟，以研究不同尺寸和形状溶质离子周围的氧化还原电位变化及筛选情况。球形离子的有效溶质尺寸随实际溶质尺寸增加，尽管比预期的增长速度慢。四面体或正方形平面离子的有效溶质尺寸随实际配体尺寸变化很小。通过参考离子周围溶剂中的电荷密度来阐明这些结果，电荷密度也用于计算溶剂中的电位。尽管电荷密度振荡会进一步传播到液体中，但筛选在溶质离子周围1纳米内基本完成。将结果与理论模型进行了比较，并讨论了对实验的影响。
