Computational studies of the cationic aluminium(chloro) hydroxides by quantum chemical ab initio methods

Abstract

Cationic aluminium(chloro) hydroxide complexes with two to four aluminium atoms were studied using quantum chemical methods. Complexes were studied in both gas and liquid phase. The liquid environment was modeled by using a conductor-like screening model (COSMO). COSMO calculations were carried out as a single point calculation at the optimized gas phase structures. Water (epsilon = 78.54) was used as the solvent. The minimum energy structures obtained from the gas phase studies were mostly compact cyclic structures. Aluminium preferred to be five-coordinated in oxygen rich clusters. Core oxygen preferred three-fold coordination but in the largest clusters the four-coordinated oxygen was observed. Water reacted dissociatively with hydrogen poor clusters. The COSMO calculations showed that the optimal structures of cationic aluminium(chloro) hydroxides tend to be more open in the liquid than in the gas phase.

Study on chemical speciation in aluminum chloride solution by ESI‐Q‐MS

“…The bridging structure is supposed to be more stable than the associated structure with electrostatic force. The discussion of these structures is very important when the formation of aluminum polymers and the precipitation of aluminum ions are considered 15–17…”

Structure and dynamics of the hydration shells of the Zn2+ ion from ab initio molecular dynamics and combined ab initio and classical molecular dynamics simulations

“…Therefore, many-body interactions, including polarization, are included in a parameter free way as the simulation proceeds. For highly charged ions, it has been demonstrated that AIMD works reliably [12][13][14]21 and we will show that there is very good agreement between simulated extended x-ray absorption fine structure ͑EXAFS͒ spectra and the results of measurements.…”

“…However, it has been recently demonstrated that a QM/MM approach in which the dynamics in the QM region is treated using a fast AIMD solver ͑herein called AIMD/MM methods͒ has been shown to greatly improve performance for dynamical calculations. 12 In this study we report Zn 2+ + 64H 2 O 300 K AIMD, Zn 2+ +6H 2 O / 58H 2 O 300 K AIMD/MM, and Zn 2+ +6H 2 O / 250H 2 O 300 K AIMD/MM ͑all the first shell water molecules are AIMD and the rest are MM͒ simulations based on density functional theory ͑DFT͒. Our primary focus is on the elucidation of the transition from a highly structured and strongly polarized first solvation shell to the bulk structure of water, as well as comparisons with putative structural interpretations used to analyze various existing x-ray and neutron scattering data.…”

“…9͒ based on empirical potentials or by ab initio molecular dynamics ͑AIMD͒. 10,11 Modeling charged ions in solution is challenging because the water molecules surrounding the ion are strongly polarized; [12][13][14] we have recently reported water dipole moments increasing by Ϸ1 D relative to bulk water values for the first hydration shells of the Al 3+ and Fe 3+ ions. 14 In this article, we report simulation of the properties of the Zn 2+ ion.…”

Identification of hydrolysis products of AlCl3·6H2O in the presence of sulfate by electrospray ionizationtime-of-flight mass spectrometry and computational methods

“…At this point, computational chemistry is introduced to determine the structures of the complexes. 43 Our group has earlier demonstrated the power of computational chemistry for investigating the structures of polymeric aluminium species. 43,44 Here, we used computational methods (DFT, MP2) based on quantum mechanics to resolve the structures of the aluminium species detected in the experimental part of the study.…”