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Critical Evaluation of Thermodynamic Properties for Halobenzoic Acids Through Consistency Analyses for Results from Experiment and Computational Chemistry



Robert D. Chirico, Andrei F. Kazakov, Ala Bazyleva, Vladimir Diky, Kenneth Kroenlein, Vladimir N. Emel'yanenko, Sergey P. Verevkin


Thermodynamic properties of the twelve monohalobenzoic acids are critically evaluated through application of computational chemistry methods for the ideal-gas phase and thermodynamic consistency assessment of properties determined experimentally and reported in the literature, including enthalpies of combustion, enthalpies of sublimation, and enthalpies of fusion. The compounds of interest are the 2-, 3-, and 4-halo isomers of fluoro, chloro-, bromo-, and iodobenzoic acids. Computations were validated by comparison with critically evaluated entropies and heat capacities in the ideal-gas state for benzoic acid, benzene, and some halobenzenes. Experimental enthalpies of formation for 2- and 3-bromobenzoic acid, measured by well-established research groups, are mutually inconsistent and are shown to be inconsistent with the computations and assessment in this work. Origins of the discrepancies are unknown, and recommended values for these compounds are based on computations and enthalpies of sublimation validated, in part, by structure-property (i.e., group-additivity) analysis. Lesser, but significant, inconsistencies between experimental and computed results are demonstrated also for 3- and 4-iodobenzoic acid. Comparison of enthalpies of formation based on experiment and computation for the ideal-gas state of 1- and 2-chloro-, bromo-, and iodo-naphthalenes provides additional support for the findings for the halobenzoic acids, as well as reveals some anomalous results in the experimental literature for the chloronaphthalenes. Computations are discussed in detail to demonstrate the approach required to obtain optimal results with modern quantum chemical methods.
J. Phys. & Chem. Ref. Data (JPCRD) -


enthalpy of formation, enthalpy of sublimation, enthalpy of vaporization, enthalpy of fusion, group additivity, halobenzoic acids, structure-property relationship, quantum-chemical methods


Chirico, R. , Kazakov, A. , Bazyleva, A. , Diky, V. , Kroenlein, K. , Emel'yanenko, V. and Verevkin, S. (2017), Critical Evaluation of Thermodynamic Properties for Halobenzoic Acids Through Consistency Analyses for Results from Experiment and Computational Chemistry, J. Phys. & Chem. Ref. Data (JPCRD), National Institute of Standards and Technology, Gaithersburg, MD, [online],, (Accessed April 17, 2024)
Created June 13, 2017, Updated October 12, 2021