Crystalline and liquid vapour pressures of the four p-monohalophenols: A thermodynamic study of their phase transitions

The influence of the halogen atoms and acetyl group on vapour pressures and related properties of the p -haloacetophenones

“…Similarly to what was observed for p-halobenzoic acids [6], methyl p-halobenzoates [6], and p-halophenols [7], the experimental results of the standard Gibbs energy and enthalpy of sublimation of the p-halogenated acetophenones studied are well fit by the straight line represented by equation (9) When considering simultaneously both the temperature of fusion and the enthalpy of sublimation as independent variables, a single correlation, described by equation (10) and represented in figure 3, relates the results of the p-haloacetophenones (studied in this work), and of the compounds of the halogenated families studied before, p-halobenzoic acids [6], methyl p-halobenzoates [6] and p-halophenols [7], and benzene:…”

“…The electrocarboxylation of aromatic ketones, namely the halogenated members of the family, ''is potentially an easy way to prepare carboxylated products, some of them of industrial interest, particularly for the production of anti-inflammatory drugs" [15]. The selection of the halogenated derivatives of acetophenone for this study is also due to our interest in investigating whether enthalpies and vapour pressures of sublimation or vaporisation of halogen substituted benzenes show a regular dependence on the volume of the halogen atom as was observed previously for p-halogenated benzoic acids, methyl benzoates, and phenols [6,7]. In a recent study [9] on the estimation of thermodynamic vaporisation properties of mono and poly halogenated benzenes it was concluded that the influence of volume in poly halogenated benzenes is not additive per se but a suitable combination of volume and electron affinity enables good estimations of the vaporisation properties from the number of the constituent halogen atoms.…”

“…Our research group has been developing equations correlating thermodynamic properties of sublimation and vaporisation of organic compounds for a period of time [1][2][3][4][5][6][7][8][9]. These correlations are very useful to test the internal coherency of the experimental results and to predict results for compounds not studied experimentally.…”

“…These correlations are very useful to test the internal coherency of the experimental results and to predict results for compounds not studied experimentally. Some of these correlations include the temperature of fusion and describe accurately vapour pressures of several para substituted benzoic acids, methyl benzoates and phenols [5][6][7]. More recently [8], it was proposed a new method for estimating vapour pressures and enthalpies of sublimation of substituted benzenes that may be applied to 30 different substituents attached to the benzene ring in different positions.…”

Prediction of enthalpy and standard Gibbs energy of vaporization of haloaromatics from atomic properties

“…In previous works correlations derived for p-halogenated benzoic acids and methyl benzoates (Almeida and Monte, 2013a), and for p-halogenated phenols (Almeida and Monte, 2013b) show a regular dependence of vapor pressures and enthalpies of sublimation or vaporization on the volume of the halogen substituent. In order to investigate if this influence is additive in terms of the constituent halogen atoms we collected experimental results of vapor pressure and enthalpies of vaporization of a series of halobenzenes.…”