Apparent oxygen reduction reaction rate

Surprisingly, the chlorate concentration in the melt is reported to remain at the level (0.004 mole %) at which it was initially present in the lithium perchlorate. This would seem to make it improbable that chlorate is an intermediate in the reaction. However, the chlorate analyses published could correspond only to upper limits of experimental uncertainty. The reactions appear to be homogeneous and unaffected by substantial additions of lithium hydroxide or of lithium nitrate. There is at least an apparent rate reduction on addition of sodium nitrate or on passage of oxygen through the melt. Since these last rate measurements were made by chloride analysis (and not by spectrophotometry for nitrite or nitrate as in other cases), diversion of an intermediate may explain all or some of them. 

The reverse reaction, oxidation of AP by GS (the latter formed by reaction of OH with GSH), was found by pulse radiolysis to have a rate constant of ca. 3 x 10 dm moP s [66], and AP " was sufficiently stable for it to be produced by steady state radiolysis via oxidation by Brj " and mixed with GSH in a stopped-flow apparatus. The forward reaction had a half life of ca. 120 ms with 0.2 mmol dm GSH at pH 5.6, with an apparent, kgf ca. 2-3 x 10 dm moP s". Thus the apparent Kg was ca. lO". Even though thermodynamically unfavourable, the reaction can readily proceed towards the right hand side through to complete reduction of AP because the product GS is removed from the equilibrium efficiently via conjugation (3) followed by (4) in oxygenated systems, or reactions (3) and (10) in the absence of oxygen ... 

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