Solubility of organics

In this section we will describe the basic principles required to estimate and calculate the solubility of an organic solute in different solvents and explain how to assess mixed solvents. 

---

Klopman G, S Wang and D M Balthasar 1992. Estimation of Aqueous Solubility of Organic Molecule by the Group Contribution Approach. Application to the Study of Biodegradation. Journal c Chemical Information and Computer Science 32 474-482. 

Divide the saturated solution of n-butyl alcohol in water into three approximately equal parts. Treat these respectively with about 2-5 g. of sodium chloride, potassium carbonate and sodium hydroxide, and shake each until the soli have dissolved. Observe the effect of these compounds upon the solubility of n-butanol in water. These results illustrate the phenomenon of salting out of organic compounds, t.e., the decrease of solubility of organic compounds in water when the solution is saturated with an inorganic compound. The alcohol layer which separates is actually a saturated solution of water in n-butyl alcohol. 

Non-aqueous microemulsions have been prepared by replacing water with formamide, a highly structured polar solvent [71]. Formamide enhances the solubility of organic compounds and is also used as a reactant. 

Balakin KV, Ivanenkov YA, Skorenko AV, Nikolsky YV, Savchuk NP, Ivashchenko AA. In silico estimation of DMSO solubility of organic compounds for bioscreening. J Biomol Scr 2004 9 22-31. 

Catana, C., Gao, H., Orrenius, C., Stouten, P. F. Linear and nonlinear methods in modeling the aqueous solubility of organic compounds. 

Hansch, C., Quinlan, J. E., Lawrence, G. L. The linear free-energy relationship between partition coefficients and the aqueous solubility of organic liquids. 

S. Prediction of aqueous solubility of organic compounds using a quantitative structure-property relationship. J. Pharm. Sd. 2002, 91,1838-1852. 

Wakita, K., Yoshimota, M., Miyamoto, S., Watanabe, H. A method for calculation of the aqueous solubility of organic compounds by using new fragment solubility constants. Chem. Pharm. Bull. 1986, 34, 4663 681. 

Metal ions in aqueous solution exist as complexes with water. The solubility of organic compounds in water depends primarily on their polarity and their ability to form hydrogen bonds with water. Organic compounds with a large part of polar components such as acetic acid, dissolve in water without limit. In such cases, the polar part dominates. By contrast, soaps and detergents have a polar end attached to a relatively large nonpolar part of the molecule. They have limited solubility and the molecules tend to coalesce to form micelles. 

Solubility of the water/benzene system (taken from Seidell, A. S., Solubilities of Organic Compounds, 3rd edn, Vol. II, 1941, Van Nostrand). 

In addition, dissolved organic carbon (DOC) is also an important soil solution solute affecting speciation and bioavailability of many trace elements in soil solution. Many trace elements and heavy metals complex with dissolved organic carbon. This is especially important in arid and semi-arid environments since high soil pH increases the solubility of organic molecules and accordingly increases concentrations of dissolved organic carbon in soil solution. 

Dissolved organic carbon and plant- or microbe- produced phytosiderophores increase the solubility of most trace elements in arid and semi-arid soils. This is especially important in arid regions. High pH increases the solubility of organic matter as dissolved organic carbon in arid soils. Copper, lead and nickel have a strong tendency to form complexes, while Cd complexes are weaker. Zinc, cobalt and manganese are... 

Prediction of aqueous solubility of organic compounds from molecular structure, J. Chem. Inf. Comput. Sci. 1998, 38, 489-496. 

D. M., Estimation of aqueous solubility of organic molecules by the group contribution approach. Application... 

Kamlet, M. J., Doherty, R. M., Abboud, J. L., Abraham, M. H., Taet, R. W., Linear solvation energy relationships 36. Molecular properties governing solubilities of organic nonelectrolytes in water, J. Pharm. Sci. 1986, 75, 338-349. 

Baneijee, S. (1985) Calculation of water solubility of organic compounds with UNIFAC-derived parameters. Environ. Sci. Technol. 19, 369-370. 

Gtickel, W., Kastel, R., Lawerenz, J., Synnatschke, G. (1982) A method for determining the volatility of active ingredients used in plant protection. Part III The temperature relationship between vapour pressure and evaporation rate. Pestic. Sci. 13,161-168. Hafkenscheid, T. L., Tomlinson, E. (1981) Estimation of aqueous solubilities of organic non-electrolytes using liquid chromatographic retention data. J. Chromatogr. 218, 409 -25. 

Klopman, G., Wang, S., Balthasar, D. M. (1992) Estimation of aqueous solubility of organic molecules by the group contribution approach. Application to the study of biodegradation. J. Chem. Inf. Comput. Sci. 32, 474-482. 

Lande, S. S., Baneijee, S. (1981) Predicting aqueous solubility of organic nonelectrolytes from molar volume. Chemosphere 10,751-759. 

Lo, J. M., Tseng, C. L., Yang, J. Y. (1986) Radiometric method for determining solubility of organic solvents in water. Anal. Chem. 58, 1596-1597. 

Nirmalakhandan, N. N., Speece, R. E. (1988a) Prediction of aqueous solubility of organic chemicals based on molecular structure. Environ. Sci. Technol. 22, 328-338. 

---