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, r(2) = 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 - 0.203R(2) + 0.560 pi (H)(2) +3.560 Sigma alpha (H)(2) + 0.702 Sigma beta (H)(2) +0.939logL(16), n = 156, r(2) = 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: R(2) is an excess molar refraction, pi (H)(2) the dipolarity/polarisability, Sigma alpha (H)(2) the overall or summation hydrogen-bond acidity, Sigma beta (H)(2) the overall or summation hydrogen-bond basicity and L(16) 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. (C) 2001 Elsevier Science Ltd. All rights reserved.