X-ray absorption spectroscopy studies of ionic association in aqueous solutions of zinc bromide from normal to critical conditions

Simonet, Virginie; Calzavara, Y.; Hazemann, Jean‐Louis; Argoud, R.; Geaymond, Olivier; Raoux, D.

doi:10.1063/1.1490588

Cited by 36 publications

(32 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This destructive interference is also present for the GaBr 3 FT signal. Such a feature has already been observed for the ZnBr 2 system [9].…”

Section: Br Anions Solvation Structuresupporting

confidence: 49%

“…A limitation of the ionpairing occurs close to the supercritical temperature and along the critical isochore: the onset of density fluctuations promotes the development of dense dynamic clusters of water molecules around the ions, leading to a screening effect which possibly inhibits the ion pairing processes [13]. Previous studies of MBr 2 (M = Mn [11], Ni [7], Zn [8][9] In the present study we focus our effort on the trivalent cation, Ga…”

Section: Introductionmentioning

confidence: 99%

“…The behaviour with P and T of the bromide anion associated to monovalent [4][5][6] or divalent cations [7][8][9][10][11] as counter ions in aqueous solutions is now well understood. The effect of ion-pairing in aqueous solutions, i.e.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

X-ray absorption spectroscopy study of solvation and ion-pairing in aqueous gallium bromide solutions at supercritical conditions

Silva¹,

Proux²,

Hazemann³

et al. 2009

Journal of Molecular Liquids

View full text Add to dashboard Cite

“…This destructive interference is also present for the GaBr 3 FT signal. Such a feature has already been observed for the ZnBr 2 system [9].…”

Section: Br Anions Solvation Structuresupporting

confidence: 49%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

X-ray absorption spectroscopy study of solvation and ion-pairing in aqueous gallium bromide solutions at supercritical conditions

Silva¹,

Proux²,

Hazemann³

et al. 2009

Journal of Molecular Liquids

View full text Add to dashboard Cite

“…Bromine-containing compounds have been intensively investigated by XAS during the last 40 years 43,44 , in order to learn more about their fundamental properties [45][46][47][48][49][50][51] , their multi-electron excitations 52,53 , or to address geological and environmental problems 54,55 . They represent an important family of natural and synthetic compounds.…”

Section: Introductionmentioning

confidence: 99%

On the sensitivity of hard X-ray spectroscopies to the chemical state of Br

Bordage

Pápai

Sas

et al. 2013

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

The sensitivity of the 1s X-ray emission and high-energy-resolution fluorescence-detected X-ray absorption spectroscopies (XES and HERFD-XAS) to resolve the variations of the chemical state (electronic structure and local coordination) of Br has been investigated for a selected set of compounds including NaBrO 3 , NH 4 Br and C 2 H 4 Br 2 (1,2-dibromoethane). For the Br K-edge XAS, employing the HERFD mode significantly increases the energy resolution, which demonstrates that with a crystal spectrometer used as detector the absorption technique becomes a more powerful analytical tool. In the case of XES, the experimental results as well as the density functional theory (DFT) modeling both show that the chemical sensitivity of the main 1s diagram emission lines (Kα 1,2 and Kβ 1,3 ) is rather limited. However, the valence-to-core (Kβ 2 ) region of XES displays significant shape and intensity variations, as expected for transitions having the same final states as those of photoemission spectroscopy. The spectra are in good agreement with the molecular orbital description delivered by DFT calculations. Calculations for an extended series of Br compounds confirm that valence-to-core XES can serve as a probe for chemical analysis, and, being a hard X-ray photon-in/photon-out technique, it is particularly well-suited for in situ investigations of molecular transformations, even on the ultrafast time scales down to femtosecond time resolution.

show abstract

“…This observation is in contrary to the situation in supercritical water where, following the dehydration of Br 1-ions, R Br-O always becomes larger. 23 Such details about the behavior of ions entering the interfacial water are unlikely to be revealed by dielectric constant measurement.…”

Section: Resultsmentioning

confidence: 99%

Coordination variation of hydrated Cu2+/Br1− ions traversing the interfacial water in mesopores

Wang

Huang

et al. 2012

AIP Advances

View full text Add to dashboard Cite

Resolution of the atomistic and electronic details about the coordination structure variation of hydrated ions in the interfacial water is still a tough challenge, which is, however, essentially important for the understanding of ion adsorption, permeation and other similar processes in aqueous solutions. Here we report the tracing of coordination structure variation for hydrated Cu2+/Br1- ions traversing the interfacial water in Vycor mesopores (ϕ = 7.6 nm) by employing both X-ray absorption near edge structure and extended X-ray absorption fine structure spectroscopies. By controlled desorption/adsorption of water, the filling fraction of the mesopores, thus the water layer thickness, can be adjusted, which in turn effects the variation of coordination structure of the ions therein. It is found that both Cu2+ and Br1- ions prefer staying exclusively in the core water, and in this circumstance no ion pairs have been detected in the solution of concentrations up to 1.0 M. Following capillary decondensation occurring at a filling fraction of ∼35% which corresponds to a water layer of about three monolayers, Br1- ions begin immediately to reconstruct their first coordination shell, characterized by ionic dehydration, shrinkage of ion-water bond length, and formation of ion pairs. In contrast, Cu2+ ions can retain a bulk-like coordination structure till being driven to bond directly to the pore surface when the filling fraction is below 20%. At the final stage of dehydration via thermal vacuum treatment at 110°C, Cu2+ ions can be completely reduced to the Cu1+ state, and recover at room temperature only when the filling fraction is above 14%. These results may be inspirable for the investigation of similar problems concerning hydrated ions in water solution under different confining conditions.

show abstract

X-ray absorption spectroscopy studies of ionic association in aqueous solutions of zinc bromide from normal to critical conditions

Cited by 36 publications

References 44 publications

X-ray absorption spectroscopy study of solvation and ion-pairing in aqueous gallium bromide solutions at supercritical conditions

X-ray absorption spectroscopy study of solvation and ion-pairing in aqueous gallium bromide solutions at supercritical conditions

On the sensitivity of hard X-ray spectroscopies to the chemical state of Br

Coordination variation of hydrated Cu2+/Br1− ions traversing the interfacial water in mesopores

Contact Info

Product

Resources

About