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The Heat of Formation of the Uranyl Dication: Theoretical Evaluation Based on Relativistic Density Functional Calculations
Author(s) -
Moskaleva Lyudmila V.,
Matveev Alexei V.,
Krüger Sven,
Rösch Notker
Publication year - 2005
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200500628
Subject(s) - uranyl , standard enthalpy of formation , actinide , dication , chemistry , density functional theory , thermodynamics , relativistic quantum chemistry , molecule , basis set , computational chemistry , atomic physics , physics , inorganic chemistry , ion , organic chemistry
By using a set of model reactions, we estimated the heat of formation of gaseous UO 2 2+ from quantum‐chemical reaction enthalpies and experimental heats of formation of reference species. For this purpose, we performed relativistic density functional calculations for the molecules UO 2 2+ , UO 2 , UF 6 , and UF 5 . We used two gradient‐corrected exchange‐correlation functionals (revised Perdew–Burke–Ernzerhof (PBEN) and Becke–Perdew (BP)) and we accounted for spin‐orbit interaction in a self‐consistent fashion. Indeed, spin‐orbit interaction notably affects the energies of the model reactions, especially if compounds of U IV are involved. Our resulting theoretical estimates for Δ f ${H{{^{o}\hfill \atop 0\hfill}}}$ (UO 2 2+ ), 365±10 kcal mol −1 (PBEN) and 370±12 kcal mol −1 (BP), are in quantitative agreement with a recent experimental result, 364±15 kcal mol −1 . Agreement between the results of the two different exchange‐correlation functionals PBEN and BP supports the reliability of our approach. The procedure applied offers a general means to derive unknown enthalpies of formation of actinide species based on the available well‐established data for other compounds of the element in question.