Equilibria in alkaline solutions of periodates

The Electroreduction of Periodate Anion in Alkaline Media

“…Values of Kb3 at zero ionic strength were calculated using single ion activity coefficients estimated according to Davies' equation (15). The weighted average for Kb, (p = 0) from the results in Table 1 is (1.53 f 0.14) x lo-', a result which agrees well with that of Buist et al (9). As expected, 'Strictly speaking this calculation should be based on Kouteck$'s equation (13) for the diffusion limited current which includes a correction for electrode sphericity.…”

“…These changes are attributed respectively to the effects of ionic atmosphere on diffusion of the reacting ions, and to the participation of more than one ion in the mass transfer process. According to the equilibrium constants determined by Buist et al (9), both H3106'-and H21063-were present in the solutions to a significant extent under the given experimental conditions. For a stoichiometric periodate concentration of 5 x 10-4M, the concentration of H,I,O ,04-was negligible except at lower pH.…”

“…The equilibrium constants and activity coefficients were calculated as described above, Kb2(p = 0) being set equal to 2.05 x (9). Results at p = 0.01 and 0.02 are presented in the form of corrected Tafel plots in that the rate constant for reduction of the monovalent species was always greater than that for the divalent species at a given ionic strength.…”

“…On the basis of existing thermodynamic data for the solution equilibria of periodate (6), he assumed that the predominant species at high p H was H310,2-and concluded that the p H dependence resulted from the fact that the electroactive species was H4106-formed from the dinegative anion in a labile protonation reaction preceding electron transfer. However, more recent studies of periodate equilibria (7)(8)(9) have shown that the species H21063-and H2I2OIo4-are present in the pH range 11-14 so that p H dependence also results from variations in the bulk concentrations of the various anions. On reexamining the double layer effect in this system, it was found that the charge on the predominant reacting species depended on both p H and ionic strength (101.…”

Synthesis and Crystal Structure of Bis pyridinium 1,2-Ethane periodate

“…1 Periodic acid is a strong oxidant, and their salts such as some ammonium periodate compounds are frequently used to oxidize a variety of functional groups; 2-5 so, the application of periodate-based compounds in organic synthesis has been extensively reviewed. 6 Here, we report on the synthesis and single crystal X-ray determination of the title salt; bis pyridinium 1,2-ethane periodate (Fig. 1).…”