A spectroscopic and computational study of Al(III) complexes in sodium cryolite melts: Ionic composition in a wide range of cryolite ratios

作者：Nazmutdinov Renat R^*; Zinkicheva Tamara T; Vassiliev Sergey Yu; Glukhov Dmitri V; Tsirlina Galina A; Probst Michael

来源：Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy , 2010, 75(4): 1244-1252.

DOI：10.1016/j.saa.2009.12.035

• Cryolite melts
• Density functional theory
• Raman spectroscopy
• Al(III) fluorocomplexes

The structure of sodium cryolite melts was studied using Raman spectroscopy and quantum chemical calculations performed at the density functional theory level. The existence of bridged forms in the melts was argued first from the analysis of experimental Raman spectra. In the quantum chemical modelling emphasis was put on the construction of potential energy surfaces describing the formation/dissociation of certain complex species. Effects of the ionic environment were found to play a crucial role in the energetics of model processes. The structure of the simplest possible polymeric forms involving two Al centres linked through F atoms ("dimers") was thoroughly investigated. The calculated equilibrium constants and model Raman spectra yield additional evidence in favour of the dimers. This agrees with a self-consistent analysis of a series of Raman spectra for a wide range of the melt composition.

• 出版日期2010-4