Models for liquid–liquid partition in the system propylene carbonate–organic solvent and their use for estimating descriptors for organic compounds

Abstract

Partition coefficients for varied compounds were determined for the organic solvent-propylene carbonate biphasic partition system where the organic solvent is n-heptane, isopentyl ether or 1-octanol. These partition coefficient databases are analyzed using the solvation parameter model facilitating a quantitative comparison of the propylene carbonate-based partition systems with other totally organic partition systems. Propylene carbonate is a weak to intermediate cohesive solvent, reasonably dipolar/polarizable and hydrogen-bond basic, and weak hydrogen-bond acidic. Propylene carbonate-organic solvent systems offer a complementary approach to other totally organic biphasic partition systems for sample preparation and descriptor measurements of compounds virtually insoluble or unstable in water.

Abraham model correlations for describing solute transfer into 2-butoxyethanol from both water and the gas phase at 298K

“…For several of the comparisons the author likely utilized solute parameters/properties rather than solvent parameters/properties because the required information was not readily available. This was particularly true in the case of the Abraham model as solvent parameters (called process or solvent equation coefficients) had been determined for about 300 water/organic solvent, air/organic solvent, and totally organic solvents biphasic partitioning systems [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Abraham model solvent equation coefficients were not available for solvents such as acetic acid, pyridine, propionitrile, diethyl phthalate, limonene, α-pinene, α-terpineol, glycerol and 1,3-propanediol.…”

Models for Liquid–Liquid Partition in the System Ethylene Glycol–Organic Solvent and Their Use for Estimating Descriptors for Organic Compounds

“…For liquid-phase microextraction, solvent evaporation is rarely required, and this restriction on solvent selection no longer applies. This should allow a wider choice of solvents with different selectivity to be exploited as demonstrated for formamide [9] and propylene carbonate [10] with n-heptane, 1,2-dichloroethane, isopentyl ether, or 1-octanol as counter solvents. In this report, we investigate the use of ethylene glycol as a base solvent for liquid-liquid partition employing different counter solvents to extend the selectivity range of totally organic biphasic systems currently available.…”

“…The system constants and their ratios provide a quantitative description of system properties in terms of the intermolecular interactions responsible for solvation and facilitate a comparison of their properties to other biphasic solvent systems [7][8][9][10][11]. They are also required for the calculation of solute descriptors by liquid-liquid partition [7,11,16,17].…”

“…For compounds of low water solubility, and for compounds that are water unstable, predominantly aqueous biphasic systems are of limited use. Totally organic biphasic systems are an attractive alternative for these compounds [8][9][10]. For conventional methods, solvent selection is restricted to volatile solvents owing to the need to reduce the final solvent volume by evaporation to obtain concentrated extracts suitable for instrumental analysis.…”

“…Silber et al [23] studied the partitioning behavior of two dye molecules in nonaqueous reverse micellar solutions prepared from n-heptane/surfactant/ethylene glycol with a view to demonstrating the possibility of micelle formation in ethylene glycol as a solvent. The solvation parameter model in a form suitable for modeling partition coefficients for neutral compounds in biphasic ethylene glycol-containing system is set out below [7][8][9][10][12][13][14]:…”