Heats of vaporization of alkyl bromides

Svoboda, V.; Majer, Vladimı́r; Veselý, František; Pick, J.

doi:10.1135/cccc19771755

Cited by 20 publications

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“…This value was used in the following calculations. The enthalpy of vaporization for this compound was determined by calorimetry, ,, from the temperature dependence of the saturated vapor pressure, − , and by correlation-gas chromatography . When the Δ l g H m o (298.15 K) values were calculated from the vapor pressure data, the original p sat ( T ) data were fitted with the Clarke–Glew equation: − R T nobreak.25em ln ( p sat p o ) = A T / θ − B [ ( T / normalθ ) − 1 ] − C [ normalθ − T + T nobreak.25em ln ( T / normalθ ) ] where θ = 298.15 K and p o = 1 bar.…”

Section: Resultsmentioning

confidence: 99%

“…The mass of the samples corrected for the buoyancy was 1.0691 g for series 1 and 1.0025 g for series 2. The experimental heat capacities above T fus were corrected for vaporization of the liquid into the free volume of the container according to the procedures described by Hoge using the recommended data on density and the saturated vapor pressure of BuBr. , …”

Section: Methodsmentioning

confidence: 99%

“…The experimental heat capacities above T fus were corrected for vaporization of the liquid into the free volume of the container according to the procedures described by Hoge 18 using the recommended data on density 19 and the saturated vapor pressure of BuBr. 14,15 Quantum-chemical calculations were performed using the Firefly QC package 20 for calculations on bromoalkanes and the GAMESS 21 G3MP2 calculations. The optimization of geometry for the conformers and calculation of frequencies of normal vibrations were performed at the B3LYP/6-31+G(2df,p) theory level.…”

Section: ' Experimental Sectionmentioning

confidence: 99%

“…The enthalpies of fusion for BuBr determined by Timmermans and Deese differ by almost 1.5 times. The consistency of the enthalpies of vaporization − and the saturated vapor pressures − is good enough to use them for the evaluation of the standard entropy of vaporization for this compound at T = 298.15 K and, if the liquid-state entropy is known, the standard entropy of gaseous BuBr.…”

Section: Introductionmentioning

confidence: 99%

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Thermodynamics of Ionic Liquid Precursors. 1-Bromobutane and Its Isomers

et al. 2011

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The heat capacity and parameters of fusion of 1-bromobutane (BuBr) were measured in the temperature range (5 to 370) K using adiabatic calorimetry. The thermodynamic functions for the compound in the crystal and liquid states were calculated from these data. On the basis of the experimental spectroscopic data and the results of quantum-chemical calculations, the ideal-gas properties for BuBr were calculated by methods of statistical thermodynamics. The obtained entropy S m o(g; 298.15 K) = 366.9 J·K–1·mol–1 is in excellent agreement with the value 367.0 ± 1.2 J·K–1·mol–1 obtained from the experimental data. The ideal-gas thermodynamic properties were also calculated for isomeric bromobutanes and 1-butyl-3-methylimdiazolium bromide ionic liquids that allowed us to find the changes of thermodynamic properties in the reactions of synthesis of 1-butyl-3-methylimidazolium bromide isomers. The literature data on the enthalpies of formation for isomeric bromobutanes were collected, and the recommended values were developed. It was demonstrated that the synthesis of ionic liquids from bromoalkanes and 1-methylimidazole in the gas phase, unlike the liquid-phase reaction, is not a thermodynamically favorable process. It possesses more positive enthalpy changes and more negative entropy changes compared to the synthesis in the liquid phase.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: ' Experimental Sectionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Thermodynamics of Ionic Liquid Precursors. 1-Bromobutane and Its Isomers

et al. 2011

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“…The values for the 0-, m-and p-chlorobenzyl chloride and benzyl bromide were obtained from vapour pressures in Beilstein (1922Beilstein ( -1977 and for benzyl iodide, from Stephenson & Malanowski (1987). c, The value for allyl chloride is from Weast & Astle (1980) and for allyl bromide from (Svoboda et al 1977). For allyl iodide, it was obtained from vapour pressures in Nielsen & Bakbo (1985).…”

Section: 700mentioning

confidence: 99%

A Theoretical Approach to the Ferguson Principle and its Use with Non‐Reactive and Reactive Airborne Chemicals

Alarie

Nielsen²,

Abraham

1998

Pharmacology & Toxicology

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Abstract:The Ferguson principle has been widely used in toxicology to separate or indicate possible mechanisms for acute toxic effects of chemicals. However, this principle has never been adequately tested because of the lack of a database containing a sufficient number of both types of chemicals, non-reactive and reactive, that the Ferguson principle purports to separate. Such a database is now available. In this report a theoretical framework for the Ferguson principle is presented, regarding one of the acute toxicological effects of volatile airborne chemicals: sensory irritation. Previously obtained results on series of non-reactive and reactive chemicals are then used to demonstrate that the Ferguson principle can be extended to reactive chemicals by adding chemical reactivity descriptors to the physicochemical descriptors required by the Ferguson principle. This approach can be successful, provided that specific chemical reactivity mechanisms can be identified for the reactive chemicals of concern. The findings suggest that it is possible to replace the empirical Ferguson principle by formal mechanistic equations which will provide a better foundation for the understanding of the mechanisms by which airborne sensory irritants exert their action.It has been shown (Ferguson 1939;Brink & Posternak 1948;Ferguson 1951; Abraham el al. 1994) that the ratio PRO may be approximately constant (the "Ferguson rule or principle'') for non-reactive volatile organic chemicals giving rise to a particular biological effect. P is the vapour pressure (mmHg or ppm), i.e., the concentration in air of the chemical necessary to induce a given level of effect. P" (same units) is the saturated vapour pressure of the pure liquid. This approach was taken by Ferguson (1939) to demonstrate that toxic indices based on PRO would lie within a relatively narrow range (approximately a constant) for nonreactive chemicals while the measured concentrations, P, would vary widely since the phase distribution phenomenon is not taken into account when using only I?With a P/Po ratio of >0.1 or so, the mechanism by which a chemical induces the biological effect has been defined as physical: due to weak forces attraction between the chemical and the receptor biophase. A ratio <0.1 would indicate a chemical reaction, although physical mechanisms still play a role. This rule could never be tested in a satisfactory manner until recently. Using a database of 145 volatile organic chemicals inducing the same biological effect, i.e., sensory irritation, it has been demonstrated that the above rule, when used to divide the database into 56 non-reactive and 89 reactive (electrophiles) chemicals, can definitely be a good starting point (Alarie et al. 1998) as originally proposed by Ferguson (1939).

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2 Pure Liquids: References

Wohlfarth¹,

Wohlfarth²

Refractive Indices of Organic Liquids

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Heats of vaporization of alkyl bromides

Cited by 20 publications

References 0 publications

Thermodynamics of Ionic Liquid Precursors. 1-Bromobutane and Its Isomers

Thermodynamics of Ionic Liquid Precursors. 1-Bromobutane and Its Isomers

A Theoretical Approach to the Ferguson Principle and its Use with Non‐Reactive and Reactive Airborne Chemicals

2 Pure Liquids: References

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