Role of Aqueous Media in Specific Recognition of Nonpolar Groups in Molecular Aggregates.

Oxidation of a pair of associating thiols (1 and 2), each having a binding site [−C(=O)NHC(=O)NH−] and a recognition site (R 1 or R 2 ), is examined in mainly one set of binary solvent mixtures of ethanol with water and organic cosolvents at various temperatures. The selectivity (r) ― a measure of degree of recognition of 1 by 2 (or of 2 by 1) ― in the oxidation is represented by the logarithmic ratio of the yield of an unsymmetrical disulfide to twice that of a symmetrical one