@article{3027836,
    title = "Reductive Desulfurization of Mercaptoacetic Acid",
    author = "Konstantatos, J. and Kalatzis, G. and Vrachnou-Astra, E. and Katakis, D.",
    journal = "ISRN Inorganic Chemistry",
    year = "1983",
    volume = "22",
    number = "13",
    pages = "1924-1927",
    issn = "2314-470X",
    doi = "10.1021/ic00155a020",
    abstract = "Mercaptoacetate in large excess and in the pH range between 3 and 10 forms with VIII intensely yellow complexes, in two successive stages, the second of which was followed by stopped-flow methods at pH 3.6 and found to be first order in vanadium(III) and in mercaptoacetate. The activation parameters are ΔH = 57.4 kJ mol-1 and ΔS‡ ‘0.8 J mol-1 K-1. Under similar conditions VII undergoes also a two-stage complexation reaction but reacts further, giving succinic acid and hydrogen sulfide. This redox reaction is first order in vanadium(II) and in mercaptoacetate and at pH 9.6 has ΔH‡ = 50.2 kJ mol-1 and ΔS‡ = -70 J mol-1 K-1. The second-order rate constant correlates with the titration curve of mercaptoacetic acid. The results are compared to analogous results for cysteine and are interpreted on the basis of a two-step chelate ring formation involving the S″ group. The activation of the VII and VIII reactions is partly attributed to proton dissociation of the organic moiety and partly to a strain in the ring, which when combined with electron transfer leads to a break of the C-S bond. The VII-mercaptoacetate system can be regarded as an electron-storing device, which can be activated by changing the proton environment. © 1983, American Chemical Society. All rights reserved."
}