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Enthalpies of Vaporization and Sublimation of the Halogen- Substituted Aromatic Hydrocarbons at 298.15 K: Application of Solution Calorimetry Approach † † † † Boris N

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Enthalpies of Vaporization and Sublimation of the Halogen- Substituted Aromatic Hydrocarbons at 298.15 K: Application of Solution Calorimetry Approach † † † † Boris N Article pubs.acs.org/jced Enthalpies of Vaporization and Sublimation of the Halogen- Substituted Aromatic Hydrocarbons at 298.15 K: Application of Solution Calorimetry Approach † † † † Boris N. Solomonov,*, Mikhail A. Varfolomeev, Ruslan N. Nagrimanov, Vladimir B. Novikov, † † † ‡ Marat A. Ziganshin, Alexander V. Gerasimov, and Sergey P. Verevkin*, , † Department of Physical Chemistry, Kazan Federal University, Kremlevskaya str. 18, 420008 Kazan, Russia ‡ Department of Physical Chemistry, University of Rostock, Dr-Lorenz-Weg 1, 18059 Rostock, Germany *S Supporting Information ABSTRACT: Recently, the solution calorimetry has been shown to be a valuable tool for the indirect determination of vaporization or sublimation enthalpies of low volatile organic compounds. In this work we studied 16 halogen-substituted derivatives of benzene, naphthalene, biphenyl, and anthracene using a new solution calorimetry based approach. Enthalpies of solution at infinite dilution in benzene as well as molar refractions for the chlorine-, bromine-, and iodine-substituted aromatics were measured at 298.15 K. Vaporization and sublimation enthalpies of these compounds at 298.15 K were indirectly derived from the solution calorimetry data. In order to verify results obtained by using solution calorimetry, vaporization/sublimation enthalpies for 1,2-, 1,3-, 1,4-dibromobenzenes, 4-bromobiphenyl, and 4,4′-dibromobiphenyl were additionally measured by using the well established transpiration method. Experimental data available in the literature were collected and evaluated in this work for the sake of comparison with our own results. Vaporization and sublimation enthalpies of halogen-substituted aromatics under study derived by using solution calorimetry approach have been in a good agreement with those measured by conventional methods. This fact approves using of solution calorimetry for determination or validation of sublimation/vaporization enthalpies for different aromatic compounds at reference temperature 298.15 K, where the conventional experimental data are absent or in disarray. Evaluated in this work a data set has been used to establish a simple group additivity scheme for prediction of vaporization enthalpies for halogen-substituted aromatic hydrocarbons. 1. INTRODUCTION and less demanding compared to the conventional methods. Third, only a small amount (about 500 mg) of the pure sample Halogen-substituted aromatic compounds are well-known ffi environmental pollutants resulting from the incomplete (0.98 to 0.99 mass fractions are su cient) as a rule could be combustion of coal and fossil fuels, as well as of rural waste enough for the calorimetric experiment. All these facts make the incineration. Reliable thermochemical data for these molecules solution calorimetry a useful technique for the rapid evaluation are required for prediction of their environmental behavior. of vaporization/sublimation enthalpies of low volatile and However, only very few experimental data are known from the thermally unstable organic compounds. literature.1,2 Experimental determination of vaporization/ The present work is part of a broader program, aiming sublimation enthalpies of low volatile compounds using evaluation of experimental data on vaporization/sublimation conventional methods is a challenging task. Results available enthalpies of aromatic compounds using a solution calorimetry in the literature data are very often in disarray. Just recently we based approach in combination with well established conven- have developed and tested a solution calorimetry approach to tional methods. We report here a systematic determination of derive vaporization/sublimation enthalpies for a number of vaporization/sublimation enthalpies of a series of 16 halogen- aromatic and polyaromatic hydrocarbons, successfully.3 In substituted derivatives of benzene, naphthalene, biphenyl, and comparison to conventional methods, where experiment is anthracene by using the solution calorimetry and the performed at elevated temperatures, the solution calorimetry transpiration method. fi fi based approach has some crucial advantages. First, calorimetric This work has ve major goals. The rst is the experimental measurements are usually carried out directly at the reference determination of solution enthalpies of 16 halogen-substituted fi temperature 298.15 K. Following, this method is highly suitable aromatic compounds in benzene at the in nite dilution at for studies of thermally unstable compounds. Moreover, the solution calorimetry based method is free from difficulties Received: September 23, 2014 connected with proper temperature adjustment of experimental Accepted: January 20, 2015 data to 298.15 K. Second, the calorimetric procedure is quick Published: February 5, 2015 © 2015 American Chemical Society 748 DOI: 10.1021/je5008795 J. Chem. Eng. Data 2015, 60, 748−761 Journal of Chemical & Engineering Data Article Table 1. Origin, Purity, Methods of Purification, and Analysis of Halogen-Substituted Aromatic Hydrocarbons and Solvents (Benzene and Carbon Tetrachloride) chemical name source initial mole fraction purity purification method final mole fraction purity analysis method 1-bromo-4-chlorobenzene Aldrich 0.99 none GCa 1,2-dibromobenzene Alfa Aesar 0.98 distillation 0.999 GC 1,3-dibromobenzene Alfa Aesar 0.97 distillation 0.999 GC 1,4-dibromobenzene Alfa Aesar 0.98 sublimation 0.999 GC hexachlorobenzene Alfa Aesar 0.98 sublimation 0.999 GC 1-bromonaphthalene Aldrich 0.97 none GC 1-iodonaphthalene Aldrich 0.97 none GC 1,4-dibromonaphthalene Alfa Aesar 0.98 sublimation 0.998 GC 4-bromobiphenyl Alfa Aesar 0.98 sublimation 0.998 GC 4,4′-dibromobiphenyl Alfa Aesar 0.98 sublimation 0.998 GC 9-chloroanthracene Alfa Aesar 0.96 sublimation 0.995 GC 9-bromoanthracene Alfa Aesar 0.96 recrystallization 0.995 GC 9,10-dichloroanthracene Alfa Aesar 0.97 recrystallization 0.995 GC 9,10-dibromoanthracene Alfa Aesar 0.98 recrystallization 0.995 GC benzene I Vecton 0.99 distillation 0.999 GC benzene II Ekos-1 0.98 distillation 0.999 GC carbon tetrachloride Ekos-1 0.98 distillation 0.999 GC 1-propanol Acros 0.99 none GC potassium chloride Aldrich 0.99 none aGas chromatography. 298.15 K, as well as measurements of their molar refractions as from the second producer was used. For measurements of auxiliary quantities. Our second goal addresses the refinement density and refractive index both of them were taken. Carbon fi of the solution calorimetry based approach toward reliable tetrachloride was distilled over the CaH2. The nal purity of determination of vaporization/sublimation enthalpies. The benzene and carbon tetrachloride after purification was more third is compilation of vaporization/sublimation enthalpies than 0.999 according to the GC analysis (see Table 1). from the literature and additional measurements of these properties using the transpiration method. The fourth goal is 3. METHODS compilation and redetermination of the molar enthalpies of 3.1. Solution Calorimetry. Dissolution enthalpies, fusion by means of differential-scanning calorimetry (DSC). Δ HAi/S, of halogen-substituted aromatic hydrocarbons in From reconciliation of thermochemical data measured by soln benzene at 298.15 K were measured using TAM III solution different methods we hope to validate our results derived by calorimeter (TA Instruments) equipped with 100 mL glass cell. using solution calorimetry, as well as to establish a consistent The ampule breaking technique was used for dissolution of set of vaporization/sublimation enthalpies for aromatic crystalline solutes. We used about (0.01 to 0.05) g of a solute compounds under study. Finally, our aim is to study the for each experiment. The sample was weighed with balances intramolecular interactions of the substituents on the aromatic − resolution of 10 4 g. Liquid solutes were introduced into the ring in terms of deviations of vaporization enthalpies from the measuring cell with the solvent using the 100 μL syringe group additivity rules. These interactions could be used to equipped with a gold cannula. The solute was dropped in the predict values of vaporization enthalpies for unmeasured solvent by the portions of 10 μLto20μL. The portional compounds with similar structures. injection of the solute allowed controlling concentration dependence of obtained data and performing experiments 2. EXPERIMENTAL SECTION close to the infinite dilution conditions. As a rule, the mole 2.1. Materials. All halogen-substituted aromatic hydro- fraction of the solute (crystalline or liquid) in final solution was carbons were of the commercial origin with the mass fraction below 0.001. purities better than 0.97. Detailed information about samples is The detailed description of the calorimeter and dissolution presented in Table 1. Before experiments solid samples were procedure was published elsewhere.3,4 The device and purified by the repeated crystallization or by fractional experimental procedure were tested by determination of sublimation in vacuum. Liquid samples were purified by dissolution enthalpy of potassium chloride in water (17.41 ± fractional distillation at reduced pressure. The purity of samples 0.04) kJ·mol−1 (ampule breaking technique) and propan-1-ol in was analyzed by using gas chromatograph (GC) Agilent 7890 B water (−10.16 ± 0.02) kJ·mol−1 (titration technique). For equipped with the flame ionization detector. Final purities of comparison, the value of dissolution enthalpy of potassium samples under study were 0.999 after purification. Some chloride in water recommended by the ICTAC working
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