Density functional theory study and kinetic analysis of the formation mechanism of Al30O8(OH)56(H2O)2618+ (Al30) in aqueous solution

Yang, Wenjing; Qian, Zhaosheng; Lu, Bangmei; Zhang, Jing; Bi, Shuping

doi:10.1016/j.gca.2009.11.015

Cited by 21 publications

(5 citation statements)

References 75 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Benchmarking comparisons to the calculations carried out at the DFT-GGA+COSMO level were made using the Gaussian computational package, employing a DFT-PBE0 exchange-correlation functional and the PCM solvation model , with the Merz–Kollman atomic radii and using the TZVP basis set , to expand the wave function solutions. Following in the style of Yang et al, Table reports the distances between the tetrahedral aluminum and the four oxygen atoms to which it is bound, using a labeling scheme defined in Figure b. Excellent agreement between Al 30 16+ structures modeled with the two computational methods is achieved.…”

Section: Experimental Methodsmentioning

confidence: 99%

Contaminant Adsorption on Nanoscale Particles: Structural and Theoretical Characterization of Cu²⁺ Bonding on the Surface of Keggin-Type Polyaluminum (Al₃₀) Molecular Species

et al. 2013

View full text Add to dashboard Cite

The adsorption of contaminants onto metal oxide surfaces with nanoscale Keggin-type structural topologies has been well established, but identification of the reactive sites and the exact binding mechanism are lacking. Polyaluminum species can be utilized as geochemical model compounds to provide molecular level details of the adsorption process. An Al30 Keggin-type species with two surface-bound Cu(2+) cations (Cu2Al30-S) has been crystallized in the presence of disulfonate anions and structurally characterized by single-crystal X-ray diffraction. Density functional theory (DFT) calculations of aqueous molecular analogues for Cu2Al30-S suggest that the reactivity of Al30 toward Cu(2+) and SO4(2-) shows opposite trends in preferred adsorption site as a function of particle topology, with anions preferring the beltway and cations preferring the caps. The bonding competition was modeled using two stepwise reaction schemes that consider Cu2Al30-S formation through initial Cu(2+) or SO4(2-) adsorption. The associated DFT energetics and charge density analyses suggest that strong electrostatic interactions between SO4(2-) and the beltway of Al30 play a vital role in governing where Cu(2+) binds. The calculated electrostatic potential of Al30 provides a theoretical interpretation of the topology-dependent reactivity that is consistent with the present study as well as other results in the literature.

show abstract

Section: Experimental Methodsmentioning

confidence: 99%

Contaminant Adsorption on Nanoscale Particles: Structural and Theoretical Characterization of Cu²⁺ Bonding on the Surface of Keggin-Type Polyaluminum (Al₃₀) Molecular Species

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Although octahedral conformation was admitted for all the Al-F complexes in above studies, theoretical studies can further provide insights into their structures which are difficult to obtain experimentally. The combined experimental and theoretical studies indicate that the quantum chemical calculation of NMR chemical shift is very useful to test the appropriateness of molecular model and previous peak assignments (20,21). Tossell calculated 19 F and 27 Al NMR shieldings for the lower-order aqueous Al-F species (22,23), but the calculated data is absent for the higher-order species.…”

Section: Introductionmentioning

confidence: 99%

Density Functional Theory Study on Aqueous Aluminum−Fluoride Complexes: Exploration of the Intrinsic Relationship between Water-Exchange Rate Constants and Structural Parameters for Monomer Aluminum Complexes

Qian

et al. 2010

Environ. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

Density functional theory (DFT) calculation is carried out to investigate the structures, (19)F and (27)Al NMR chemical shifts of aqueous Al-F complexes and their water-exchange reactions. The following investigations are performed in this paper: (1) the microscopic properties of typical aqueous Al-F complexes are obtained at the level of B3LYP/6-311+G**. Al-OH(2) bond lengths increase with F(-) replacing inner-sphere H(2)O progressively, indicating labilizing effect of F(-) ligand. The Al-OH(2) distance trans to fluoride is longer than other Al-OH(2) distance, accounting for trans effect of F(-) ligand. (19)F and (27)Al NMR chemical shifts are calculated using GIAO method at the HF/6-311+G** level relative to F(H(2)O)(6)(-) and Al(H(2)O)(6)(3+) references, respectively. The results are consistent with available experimental values; (2) the dissociative (D) activated mechanism is observed by modeling water-exchange reaction for [Al(H(2)O)(6-i)F(i)]((3-i)+) (i = 1-4). The activation energy barriers are found to decrease with increasing F(-) substitution, which is in line with experimental rate constants (k(ex)). The log k(ex) of AlF(3)(H(2)O)(3)(0) and AlF(4)(H(2)O)(2)(-) are predicted by three ways. The results indicate that the correlation between log k(ex) and Al-O bond length as well as the given transmission coefficient allows experimental rate constants to be predicted, whereas the correlation between log k(ex) and activation free energy is poor; (3) the environmental significance of this work is elucidated by the extension toward three fields, that is, polyaluminum system, monomer Al-organic system and other metal ions system with high charge-to-radius ratio.

show abstract

“…Though the precise role of calcium and glycine in affecting this highly specific transformation is not known, it is thought that glycine buffers initial base addition and prevents nonspecific aluminum hydrolysis by weak and reversible coordination 17 to Al while calcium plays a critical role in facilitating the stepwise rotation of the trimeric subunit. 18 The herein described synthetic approach allows the Keggin isomerization process of aluminum oxo-hydroxides to occur in a step-wise manner that is not possible via conventional methods. Thus, the g-Al 13 molecule has been obtained and subsequently characterized through single X-ray diffraction and 27 Al NMR spectroscopy.…”

mentioning

confidence: 99%

Controlled step-wise isomerization of the Keggin-type Al13 and determination of the γ-Al13 structure

et al. 2013

View full text Add to dashboard Cite

show abstract

Density functional theory study and kinetic analysis of the formation mechanism of Al30O8(OH)56(H2O)2618+ (Al30) in aqueous solution

Cited by 21 publications

References 75 publications

Contaminant Adsorption on Nanoscale Particles: Structural and Theoretical Characterization of Cu²⁺ Bonding on the Surface of Keggin-Type Polyaluminum (Al₃₀) Molecular Species

Contaminant Adsorption on Nanoscale Particles: Structural and Theoretical Characterization of Cu²⁺ Bonding on the Surface of Keggin-Type Polyaluminum (Al₃₀) Molecular Species

Density Functional Theory Study on Aqueous Aluminum−Fluoride Complexes: Exploration of the Intrinsic Relationship between Water-Exchange Rate Constants and Structural Parameters for Monomer Aluminum Complexes

Controlled step-wise isomerization of the Keggin-type Al13 and determination of the γ-Al13 structure

Contact Info

Product

Resources

About

Density functional theory study and kinetic analysis of the formation mechanism of Al30O8(OH)56(H2O)2618+ (Al30) in aqueous solution

Cited by 21 publications

References 75 publications

Contaminant Adsorption on Nanoscale Particles: Structural and Theoretical Characterization of Cu2+ Bonding on the Surface of Keggin-Type Polyaluminum (Al30) Molecular Species

Contaminant Adsorption on Nanoscale Particles: Structural and Theoretical Characterization of Cu2+ Bonding on the Surface of Keggin-Type Polyaluminum (Al30) Molecular Species

Density Functional Theory Study on Aqueous Aluminum−Fluoride Complexes: Exploration of the Intrinsic Relationship between Water-Exchange Rate Constants and Structural Parameters for Monomer Aluminum Complexes

Controlled step-wise isomerization of the Keggin-type Al13 and determination of the γ-Al13 structure

Contact Info

Product

Resources

About

Contaminant Adsorption on Nanoscale Particles: Structural and Theoretical Characterization of Cu²⁺ Bonding on the Surface of Keggin-Type Polyaluminum (Al₃₀) Molecular Species

Contaminant Adsorption on Nanoscale Particles: Structural and Theoretical Characterization of Cu²⁺ Bonding on the Surface of Keggin-Type Polyaluminum (Al₃₀) Molecular Species