Laasonen Kari, Larrucea Julen, Sillapää Atte
Department of Chemistry, University of Oulu, P.O. Box 3000, 90014 Oulu, Finland.
J Phys Chem B. 2006 Jun 29;110(25):12699-706. doi: 10.1021/jp054876+.
We have studied a mixture of HF and HCl molecules in water using Car-Parrinello ab initio molecular dynamics (CPMD). We have done simulations with 1 HF and 3 HCl molecules, 3 HF and 4 HCl, 6 HF and 8 HCl (6/8 simulation), and 14 HF molecules. All simulations consist of 32 molecules, and they were 10-96 ps long. The HF dissociation probability was around 30%, and HCl's was more than 90%. The solvation of the HF molecule was much better than the solvation of HCl. The solvation environment of F, both the F- ion and the F in HF, did not depend much on the acids concentration, whereas the Cl coordination numbers were rather sensitive to the concentration. In the 6/8 simulation, all XH-Y (X, Y = F, Cl) type molecules were observed and the FH-F was the most probable. In general, the molecular structures in mixed aqueous acid systems were similar to the pure HF(aq) and HCl(aq) systems.
我们使用Car-Parrinello从头算分子动力学（CPMD）研究了水中HF和HCl分子的混合物。我们对1个HF分子和3个HCl分子、3个HF分子和4个HCl分子、6个HF分子和8个HCl分子（6/8模拟）以及14个HF分子进行了模拟。所有模拟均包含32个分子，时长为10 - 96皮秒。HF的解离概率约为30%，HCl的解离概率超过90%。HF分子的溶剂化作用比HCl的溶剂化作用好得多。F的溶剂化环境，无论是F⁻离子还是HF中的F，对酸浓度的依赖性不大，而Cl的配位数对浓度相当敏感。在6/8模拟中，观察到了所有XH - Y（X、Y = F、Cl）类型的分子，其中FH - F最为常见。一般来说，混合水酸体系中的分子结构与纯HF（水溶液）和HCl（水溶液）体系相似。
