1993 Volume 9 Issue 3 Pages 345-349
The aggregation number of N-octanoyl-N-phenylhydroxylamine (C8-PHA) in carbon tetrachloride was determined on the basis of the extraction equilibria of copper(II) chelate with C8-PHA between aqueous and carbon tetrachloride phases. According to the relation of the distribution ratio of copper(II) with its concentration in the organic phase, the formation of a reversed micelle consisting of approximately 13 C8-PHA molecules was deduced when C8-PHA concentration was greater than 0.1mol dm-3. The Karl Fisher titration results showed that one water molecule was included in the reversed micelle. The polar parameter (ET(1)) of the reversed micelle was determined to be 250kJ mol-1 by measuring absorption spectra of 1-(4-hydroxyphenyl)-2, 4, 6-triphenylpyridinium betaine (HPTPP) as a function of C8-PHA concentration in carbon tetrachloride. The ET(1) value was different from that in carbon tetrachloride, indicating the incorporation of HPTPP into the polar core region where the hydrophilic chelating groups are oriented inward in the reversed micelle. On the basis of the ET(1) values in organic solvents, the polar core region could be regarded as being an alcoholic medium.
