Some thermodynamic properties of dialkylsulphides and dialkyldisulphides in aqueous solution

Organic Sulfides in Hydrothermal Solution: Standard Partial Molal Properties and Role in Organic Geochemistry of Hydrothermal Environments

“…These methods take advantage of the systematic nature of the properties as a function of carbon chain length within a family of organic compounds (Shock and Helgeson 1990;Schulte and Shock 1993;Shock 1995;Dale et al 1997;Schulte 1997;Schulte and Rogers 2004) to estimate properties for those members of the family for which experimental data are not available. Such estimates accurately predict (Abraham et al 1990) and DG f,g (Domalski and Hearing 1993) e Calculated from DH g-aq (Bastos et al 1991) and DH f,g (Domalski and Hearing 1993) f Calculated from DG f = DH f -TDS f and S°(third law entropies) of the elements from Cox et al (1989) g Bastos et al (1991) h Terasawa et al (1975) Aquat Geochem (2010) 16:621-637 623 subsequently measured properties of longer-chained alkyl organic molecules (see e.g. Schulte 1997;Schulte et al 1999).…”

“…There are no direct experimental measurements of the standard partial molal Gibbs free energy of formation for aqueous alkyl sulfides. Values of D " G f and D " H f for dimethyl, diethyl and dipropyl sulfide were calculated using the standard Gibbs free energies and enthalpies of formation of the gaseous species, along with experimentally determined values of these properties of the hydration reaction taken from the literature (Abraham et al 1990;Bastos et al 1991;Domalski and Hearing 1993). The details of these calculations can be found in Plyasunov and Shock (2001) and in the footnotes of Table 1.…”

“…1 is -3,143 calories. Consequently, for the alkyl sulfides, values of D " G f at 25°C and 1 bar for longer, symmetrical alkyl chains (dibutyl to dihexyl sulfide) are calculated using the equation Table 2 Values of the thermodynamic properties and parameters for the revised Helgeson-Kirkham-Flowers equations of state for symmetrical alkyl sulfide species (Abraham et al 1990) and DG f(g) (Domalski and Hearing 1993) h Calculated from DH g$aq (Bastos et al 1991) and DH f(g) (Domalski and Hearing 1993) where n is the number of carbon atoms in the alkyl chain. The resulting values are reported in Table 2.…”

“…Experimental values of the partial molal heat capacity for dimethyl, diethyl and dipropyl sulfide were determined by Bastos et al (1991). These values are shown in Fig.…”

“…The line represents a best fit to these data with a slope of 6.7 cal mol -1 K -1 n -1 (see text) Fig. 4 Standard partial molal heat capacities (C P ) in calories per mole per Kelvin of aqueous alkyl sulfides (taken from Bastos et al 1991) as a function of total number of carbon atoms in the alkyl chain (n). The line represents a best fit to these data with a slope of 21.2 cal mol -1 K -1 n -1 (see text) slope of a best fit line for the experimental data, the computed intercept shown in Fig.…”