On the basis of the simple two-phase model the partition constants (Kd) of various organic solutes and metal chelates between aqueous and Triton X-100 micellar phases are derived spectrophotometrically. The magnitude and the order of Kd are discussed in terms of molecular size, hydrophilicity and ion-association character of the solutes. The Kd values of neutral species increase almost linearly with their van der Waals molar volumes until the critical value near 110 ml mol-1 is reached. Above this critical volume, the constraint effect of the micelles gives rise to severe levelling off the partition constants at ca. 103.0 for bulky solutes. The Kd values of 2-(thiazol-2-ylazo)-4-tert-octylphenol, 2-(thiazol-2-ylazo)-4-methylphenol (HL) and the metal chelates of [FeIIL2] and [NiIIL2] are in a very narrow range of 102.83, 102.93, 103.06 and 103.16, respectively. The effects of micellar size are also examined using Brij-35 and Brij-58 surfactants.
|Number of pages||8|
|Journal||Journal of the Chemical Society, Faraday Transactions|
|Publication status||Published - 1994 Dec 1|
ASJC Scopus subject areas
- Physical and Theoretical Chemistry