Diffusion in Weakly Coordinating Solvents
Diffusion in Weakly Coordinating Solvents
复制标题
DOI：
10.1016/j.electacta.2022.140720
复制
发表时间：
2022-06
影响因子：
6.6
通讯作者：
Alexander W. Black;Wenjian Zhang;G. Reid;P. Bartlett
中科院分区：
文献类型：
--
作者：
Alexander W. Black;Wenjian Zhang;G. Reid;P. Bartlett
弱配位溶剂对于电沉积p区半导体以应用于电子器件中是令人感兴趣的。p-嵌段络合物通常具有容易置换的弱配位配体，使得它们与强刘易斯碱性溶剂不相容。在这项工作中，我们使用电化学测量在微电极研究扩散弱配位溶剂。测量了六氟磷酸十甲基二茂铁、六氟磷酸十甲基二茂铁、六氟磷酸二茂钴以及电沉积前体四氯锑酸盐（III）和四氯铋酸盐（III）的扩散系数。使用修改后的斯托克斯-爱因斯坦方程的值进行分析，并与理论上的上限，Dmax，和下限，Dmin，边界的扩散系数进行比较。这种方法允许的解释ofD值，同时避免处理与分子大小的斯托克斯-爱因斯坦方程中的一些不确定性。发现中性十甲基二茂铁服从Stokes-Einstein方程，而带电茂金属物种的值小于理论最小值，这归因于离子配对引起的大于预期的颗粒尺寸。还强调了考虑斯托克斯-爱因斯坦方程的修改的重要性。
Weakly coordinating solvents are of interest for the electrodeposition of p-block semiconductors for application in electronic devices. p-block complexes typically have weakly coordinated ligands that are easily displaced, making them incompatible with strongly Lewis basic solvents. In this work we use electrochemical measurements at microelectrodes to study diffusion in weakly coordinating solvents. Diffusion coefficients of the metallocenes decamethylferrocene, decamethylferrocenium hexafluorophosphate, cobaltocenium hexafluorophosphate, and the electrodeposition precursors tetrachloroantimonate(III) and tetrachlorobismuthate(III) were measured. The values are analyzed using the modified Stokes-Einstein equation and compared with the theoretical upper,Dmax, and lower,Dmin, bounds of the diffusion coefficients. This approach allows the interpretation ofDvalues, whilst avoiding dealing with some of the uncertainties associated with molecular size in the Stokes-Einstein equation. The neutral decamethylferrocene was found to obey the Stokes-Einstein equation whereas the charged metallocene species had values which were less than the theoretical minimum, which was attributed to a larger than expected particle size caused by ion pairing. The importance of considering the modifications of the Stokes-Einstein equation is also highlighted.