Abstract
The spectra of iodine in the presence of iodide, iodic acid, and polyvinylpyrrolidone (PVP) were obtained. Large effects of PVP concentrations on the spectra were observed. Changes in iodine spectra in the presence of N-methyl-2-pyrrolidone and N, N-diethyl-propionamide in various solvents indicated charge-transfer type interaction in less polar solvents. The spectra of the aqueous iodine solution were more affected by the addition of PVP with a smaller degree of polymerization. Kinetic studies of hydrolysis of iodine in the absence and presence of PVP indicated that PVP accelerates hydrolysis of iodine except for the initial period. The possible mechanism of accelerated hydrolysis of iodine in the presence of PVP is complexation of triiodide ion with PVP and subsequent shifts in the hydrolysis equilibrium of iodine.
