Saukkoriipi Jaakko J, Laasonen Kari
Department of Chemistry, University of Oulu, P.O. Box 3000, Oulu FIN-90014, Finland.
J Phys Chem A. 2008 Oct 30;112(43):10873-80. doi: 10.1021/jp804176v. Epub 2008 Oct 4.
Car-Parrinello molecular dynamics (CPMD) and the static density functional method (DFT) with a conductor-like screening model (COSMO) were used to investigate the chemistry of aluminum (chloro)hydroxide in water. With these methods, the stability, reactivity, and acidic nature of the chosen chlorohydrate were able to be determined. Constrained molecular dynamics simulations were used to investigate the binding of chlorine in an aquatic environment. According to the results, aluminum preferred to be 5-fold-coordinated. In addition, the activation energy barriers for the dissociation of chlorine atoms from the original chlorohydrate structure were able to be determined. The actual values for the barriers were 14 +/- 3 and 40 +/- 5 kJ mol (-1). The results also revealed the acidity of the original cationic dimer. DFT with COSMO was used to determine free energy differences for the reactions detected in the molecular dynamic simulations. In conclusion, new results and insight into the aquatic chemistry of the aluminum (chloro)hydroxides are provided.
采用Car-Parrinello分子动力学（CPMD）和带有类导体屏蔽模型（COSMO）的静态密度泛函方法（DFT）研究了氢氧化铝（氯）在水中的化学性质。通过这些方法，能够确定所选氯水合物的稳定性、反应活性和酸性本质。利用受限分子动力学模拟研究了氯在水生环境中的结合情况。根据结果，铝更倾向于形成五配位结构。此外，还能够确定氯原子从原始氯水合物结构中解离的活化能垒。这些能垒的实际值分别为14±3和40±5 kJ mol⁻¹。结果还揭示了原始阳离子二聚体的酸性。使用带有COSMO的DFT来确定分子动力学模拟中检测到的反应的自由能差。总之，本研究提供了关于氢氧化铝（氯）水生化学的新结果和见解。
