The solubility of gases and vapours in dry octan-1-ol at 298 K

Ostwald solubility coefficients of 74 compounds in dry octan-1-ol at 298 K have been determined, and have been combined with literature values and additional values we have calculated from solubilities in dry octan-1-ol and vapour pressures to yield a total of 161 log L^OctOH values at 298 K. These L^OctOH values are identical to gas-to-dry octan-1-ol partition coefficients, often denoted as K_OA. Application of the solvation equation of Abraham to 124 values as a training set yielded a correlation equation with n = 124, S.D. = 0.125, r² = 0.9970 and F = 7731. This equation was then used to predict 32 values of log L^OctOH as a test set, giving a standard deviation, S.D. of 0.131, an average absolute deviation of 0.085 and an average deviation of -0.009 log units. The solvation equation for the combined 156 log L^OctOH values was logL^OctOH = - 0.120 - 0.203R₂ + 0.560π₂^H + 3.560 ∑ α₂^H + 0.702 ∑ β₂^H + 0.939logL¹⁶, n = 156, r² = 0.9972, S.D. = 0.125, F =10573, where, n is the number of data points (solutes), r the correlation coefficient, S.D. the standard deviation and F is the F-statistic. The independent variables are solute descriptors as follows: R₂ is an excess molar refraction, π₂^H the dipolarity/polarisability, ∑ α₂^H the overall or summation hydrogen-bond acidity, ∑ β₂^H the overall or summation hydrogen-bond basicity and L¹⁶ is the Ostwald solubility coefficient on hexadecane at 298 K. The equation is consistent with similar equations for the solubility of gases and vapours into methanol, ethanol and propan-1-ol. It is suggested that the equation can be used to predict further values of log L^OctOH, for which the solute descriptors are known, to within 0.13 log units.