NEW AND SURPRISING EXPERIMENTAL RESULTS FROM THE OXIDATION OF SULFINIC AND SULFONIC-ACIDS

Thiourea, (H2N)(2)C=S, aminoiminomethanesulfinic acid, H2N(HN=)CSO2H ( AIMSA), and aminoiminomethanesulfonic acid, H2N(HN=)CSO3H (AIMSOA) are all oxidized by mild oxidizing agents to a sulfate and an organic res idue. AIMSA and AIMSOA are the postulated intermediates in the oxidati on pathway of thiourea to sulfate. The oxidation of AIMSOA is accompan ied by a cleavage of the C-S bond to form sulfate. Surprisingly, fresh ly prepared solutions of AIMSOA are oxidized by the common oxidants (o xyhalogens and halogens) at rates that are much slower than oxidation rates of AIMSA by the same oxidants. These results seem to suggest tha t AIMSOA may be structurally different from AIMSA and that the decompo sition of AIMSOA to HSO3- is the prerequisite to its oxidation. The ox idation pathway of AIMSA to SO42- also proceeds through the formation of HSO3- and not predominantly through AIMSOA.