Organomercury compounds: XVI. Thermal decomposition reactions of mercuric arenesulphonate dihydrates

P. G. Cookson, G. B. Deacon

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Thermal decomposition of the mercuric arenesulphonate dihydrates Hg(O3SR)2,- 2H20 (R = C6X5, p-HC6X4, or m-HC6Cl4; X = Cl or F) at c. 130-240° gave the corresponding diarylmercurials, the polyhalogenobenzenes RH, and sulphur trioxide (or sulphuric acid) in all cases, together with RSO3H (R = C6F5 or p-HC6F4), and p-(p-HC6F4SO3Hg)2C6F4. By contrast, decomposition of Hg(O3SR)2, 2H2O (R = m-HC6F4 or o-HC6X4) gave the corresponding (-HgC6X4SO3-)n derivatives, sulphonic acids, polyhalogenobenzenes, and sulphur trioxide in all cases, together with m-HC6F4HgO3S-m-HC6F4 and o-(o-HC6Cl4SO3Hg)2C6Cl4. The compounds RHgO3SR (R = C6Cl5, isolated as the monopyridinate, or p-HC6Cl4) were obtained from decomposition of the appropriate mercuric sulphonates at c. 165°. Identities of (-HgC6X4SO3-)n derivatives were established mainly by cleavage with triiodide ions in N, N-dimethylformamide giving the salts M(IC6X, SO3) (M = Na or S-benzylthiouronium), and of (HC6X4SO3Hg)2C6X4 derivatives by similar degradation giving I2C6X4 and M(HC6X4SO3) (M = Na or Ph4As). Similar degradation of C6Cl5HgO3SC6Cl5, py, p-HC6Cl4HgO3S-p-HC6Cl4, and the known mercurials C6Cl5HgCl, (p-HC6Cl4)2Hg, and (o-HC6Cl4)2Hg gave the corresponding iodopolychlorobenzenes. The mercurated derivative (-o-HgC6F4SO3-)n gave (-o-HgC6F4-)3 on thermal decomposition, and crystallization from water yielded (-o-HgC6F4SO3-)n, 2nH2O, which was converted into (Ph4As)(o-ClHgC6F4SO3) by tetraphenylarsonium chloride. The mercuric sulphonates were prepared from mercuric acetate and the appropriate sulphonic acids in acetic acid (X = Cl) or water (X = F). Sulphonic acids, obtained by sulphonation reactions, were characterized as the dihydrates and in some cases sodium salts (polychloro derivatives) or as barium and tetraphenylarsonium salts (tetrafluoro derivatives).

Original languageEnglish
Pages (from-to)541-555
Number of pages15
JournalAustralian Journal of Chemistry
Issue number3
Publication statusPublished - 1 Jan 1973

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