THERMOCHEMICAL INVESTIGATIONS OF HYDROGEN-BONDED SOLUTIONS .5. DEVELOPMENT OF PREDICTIVE EQUATIONS FOR THE SOLUBILITY OF ANTHRACENE IN BINARY ALCOHOL PLUS ALCOHOL MIXTURES BASED UPON MOBILE ORDER THEORY

The unconventional solution model of Mobile Order, which had previousl y been shown to provide a very accurate thermodynamic description of a nthracene solubilities and chemical potentials in binary hydrocarbon alcohol solvent mixtures, is extended to binary solvent systems conta ining two self-associating alcohol co-solvents. Expressions are derive d for predicting the solubility of crystalline solutes from a prior kn owledge of the solubility in the two pure alcohol solvents. Applicatio ns and limitations of the newly derived equations are assessed using a nthracene solubilities in binary 2-propanol + 1 -propanol, 1-butanol 1-propanol, 2-butanol + 1-propanol, 1-octanol + 1-propanol, 1-butanol + 2-propanol, 2-butanol + 2-propanol, and 1-octanol + 2-butanol mixtu res which are measured as part of the present study. The two most succ essful expressions permit each individual alcohol co-solvent to form h omogeneous hydrogen-bonded complexes. Both equations predict the exper imental anthracene solubilities to within an average absolute deviatio n of about +2%. Inclusion of terms to account for heterogeneous comple x formation between two dissimilar alcohols has little effect on the p redicted values.