Solubilities of diuron in 19 organic solvents are reported. These are combined with the solubility in water and the vapour pressure of diuron to give 19 values of water±solvent partitions, P, and 19 values of gas±solvent partitions, L. Coef®cients in the general solvation equations (i) and (ii) are known for all 38 of these systems. In equations (i) and (ii), the independent variables are solute descriptors as follows: R 2 is an excess molar refraction, p 2 H is the dipolarity/polarizability, Sa 2 H and Sb 2 H are the overall hydrogen-bond acidity and basicity, Vx is the McGowan characteristic volume, and log L 16 is a descriptor where L 16 is the solute L coef®cient on hexadecane at 298 K. log SP c rR 2 sp 2 H aSa 2 H bSb 2 H nVx i log SP c rR 2 sp 2 H aSa 2 H bSb 2 H log L 16 iiWe estimate R 2 as 1.28 and calculate Vx as 1.5992, and then solve the total set of 38 equations to yield p 2 H = 1.60, Sa 2 H = 0.57, Sb 2 H = 0.70 and log L 16 = 8.06 log units. These descriptors reproduce the 38 observed log P and log L values with a standard deviation of only 0.12 log units, and a test set of 13 independent log P and log L values with a standard deviation of 0.10 log units. Once the solvation descriptors for diuron are known, a range of physicochemical properties can be predicted; some examples are given. Similar analyses are reported for monuron and other substituted 3-phenyl-1,1-dimethylureas.

Experimental solubilities are reported for anthracene dissolved in ternary 1-propanol + 1-butanol + 2,2,4-trimethylpentane, 1-propanol + 2-butanol + 2,2,4-trimethylpentane, 2-propanol + 1-butanol + 2,2,4-trimethylpentane, and 2-propanol + 2-butanol + 2,2,4-trimethylpentane solvent mixtures at 25°C. Nineteen compositions were studied for each of the four solvent systems. Results of these measurements are used to test the predictive ability of the ternary solvent form of the combined NIMS/Redlich-Kister equation. Computations showed that the model predicted the observed solubility behavior to within an overall average absolute deviation of about 0.9%.

Experimental solubilities are reported for 2-hydroxybenzoic acid dissolved in 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 2-methyl-2-propanol, 1-pentanol, 1-octanol, dibutyl ether, 1,4-dioxane, tetrahydrofuran, ethyl acetate, butyl acetate, 2-propanone, 2-butanone, and cyclohexanone at 298.15 K. Results of these measurements reveal that the observed solubilities in the eight alcohol solvents fall within a fairly narrow mole fraction range of each other. 2-Hydroxybenzoic acid is more soluble in both 1,4-dioxane and tetrahydrofuran than in any of the other alcohol, ester, or ketone solvents studied.

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Experimental solubilities are reported at 25.0°C for diuron (also called 3-(3,4-dichlorophenyl)-1,1-dimethyl urea) dissolved in 49 different organic nonelectrolyte solvents containing ether-, chloro-, hydroxy-, ester-, methyl-, and tert-butyl-functional groups. Results of these measurements are used to test the applications and limitations of expressions derived from Mobile Order theory. For the 28 nonalcoholic solvents for which predictions could be made computations show that Mobile Order theory does provide fairly reasonable estimates of the saturation mole fraction solubilities. Average absolute deviation between predicted and observed values is 60.1%. Diuron solubilities in the alcohol solvents are used to calculate stability constants for presumed solute-solvent hydrogen bonds that are believed to occur in solution.Key words: pesticide, diuron solubilities, organic nonelectrolyte solvents, solubility predictions.