Effects of solvent medium on solubility IV: Comparison of the hydrophilic-lipophilic character exhibited by functional groups in ethanol-water and ethanol-cyclohexane mixtures.
Solvent effects on the solubility of a set of structurally related solid compounds (Ax, Ay, etc.) in ethanol-water (system 1) and ethanol-cyclohexane (system 2) are compared by the equation, log Sy = Py log Sx + C. For a given structural change, Ax----Ay, it yields the respective medium-effects parameters, Py1 and Py2. They are used to compare the sensitivity of both solvent systems with the structural changes in the substrates by the equation, delta 12 = (Py1 - 1) - (1 - Py2). Structural changes involving the full replacement of the hydrogen atoms bonded to either O or N afford delta 12 less than 0, while those involving solely an increase in the alkyl chain of the substrates yield delta 12 greater than 0. A structural change where the donor-acceptor capacity of hydrogen bonding is maintained yields a delta 12 approaching zero.
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003510:Cyclohexanes; D000431:Ethanol; D012995:Solubility; D012997:Solvents; D014867:Water
D003510:Cyclohexanes; D012997:Solvents; D014867:Water; D000431:Ethanol