Analytical potential of the interaction between triiodide ion and hexadecylpyridinium chloride micelles in an aqueous medium

Abstract

The association between triiodide ion and hexadecylpyridinium chloride (cetylpyridinium chloride; CPC) micelles is discussed. The formation of the I −1 3-CPC system under given conditions results in a bathochromic shift from 350 nm (absorption wavelength of the I − 3 complex) to 500 nm (maximum absorption wavelength of the I − 3-CPC association) in addition to a substantial increase in the absorptivity and stability constant of the triiodide complex. The interaction between I − 3 and aqueous CPC micelles was studied in depth. This novel association may be of great help in improving the photometric monitoring of reactions involving the I 2-I − pair and hence in increasing the sensitivity and selectivity of their determinations.