Thermochemistry of Neutral and Charged Vapor Complexes over NaBr-LnBr3 Systems

• Published in: ECS transactions 2012-05, Vol.41 (42), p.3-11
• Main Authors: Kudin, Lev S., Ivanov, Dmitry A.
• Format: Article
• Language: English
• ISSN: 1938-5862; 1938-6737
• DOI: 10.1149/1.4717995

The Knudsen effusion cell mass spectrometry and the density functional theory were used to study vapor species over the NaBr−LnBr3 (Ln = La, Lu) binary systems. The complex molecules NaLnBr4, Na2LnBr5 and both positive Na2LnBr4+, Na3LnBr5+ and negative NaLnBr5− complex ions have been observed in saturated vapor in the temperature range 870 - 1184 K (La) and 812 - 1065 К (Lu) for the first time along with the molecules and ions inherent to the pure components. Molecular parameters and energy characteristics were obtained by quantum-chemical calculations. The partial vapor pressures of neutral constituents have been obtained. The equilibrium constants of dissociation reactions of molecular and charged complexes were determined and the enthalpies of reactions have been calculated using the second and third laws of thermodynamics. Also the enthalpies of formation of complex molecules and ions have been obtained.