Thiocarbonate Sulphur

Thiolcarbonic Acid, HS.CO.OH, yields carbon oxysulphide, COS, by decomposition its esters yield alcohols or mereaptans when saponified, according to whether the alkyl group is attached to oxygen or to sulphur by this means the constitutions of the thiocarbonic acids are established. 

Sodium perthiocarbonate, Na2CS4, is formed when an alcoholic solution of sodium sulphide is converted into the disulphide by the addition of sulphur and subsequently treated with carbon disulphide.2 Perthiocarbonates may also be formed by the direct combination of thiocarbonates with sulphur.3 There is no analogy to this latter method of preparation in the case of percarbonates this fact is usually regarded as illustrating the superior chain-forming power of sulphur atoms as compared with oxygen atoms. 

Thiocarbonates.—The sulphocarbonates, or thiocar-bonates (from the Greek tbeion, sulphur) form a class of salts analogous to the carbonates, both in their formulae and in the method of their preparation. Carbon disulphide, a volatile liquid, boiling at 46°, possessing a disagreeable smell, is produced when sulphur vapour is led over charcoal... 

The crystal structure of the dithioacetylacetone (sacsacH) complex of cobalt(n), Co(sacsac)2, shows it to be monomeric square planar,164 in marked contrast to the acacH analogue. Pyridine 2-thiol (LH), which can exist as the thione tautomer (31) forms Co(LH)2X2 (X = Cl, Br, or I) complexes these contain the ligand bonded through the sulphur, as evidenced by the presence of a v(N—H) vibration in the i.r. spectra.165 Morpholine 4-thiocarbonic acid (32) also appears to be S-bonded in the CoL2X2 complexes (X = Cl, Br, or I), since the v(C=S) frequency is lowered upon co-ordination.166 The electronic spectra of the CoL2C12 complexes (L = thiourea, A-phenylthiourea, and TViV -diphenylthiourea) have been recorded.167... 

Platinum Thiocarbonate is obtained in combination with 2 molecules of ammonia, PtCS3(NH3)2.H20, by crystallisation from a mixture of potassium chlor-platinite, concentrated ammonia and carbon disulphide.2 It yields red needles, insoluble in cold water, ammonium or sodium hydroxide. Exposed over sulphuric acid in vacuo it becomes anhydrous. 

Applications of di- and tri-phenylpyrylium salts continue to be exploited in the synthesis of pyridines, thiocarbonates, thiocyanates, " nitriles, and NN -diaryl-carbodi-imides. Conversion of pyrylium salts into 2-acyl-furans and 2-pyrones by sulphuric acid is dependent on the concentration of the acid. ... 

Reaction of perfluoroisobutene with sulphur in the presence of caesium fluoride yields 2,4-bis(hexafluoroisopropylidene)-l,3-dithietan (bistrifluoro-methylthioketen dimer) together with the polysulphides (CF3)3C Sn-C(CF,), (n = 3 or 4). Bistrifluoromethylthioketen dimer is available by the reaction of a variety of sulphur nucleophiles, alkali-metal salts of thiocarbamates, thiocarbonates, thiocarboxylates, thiophosphates, thiosulphate, thiocyanate, hydrosulphide, etc. with perfluoroisobutene. - The reaction with... 

The total sulphur (elemental, xanthogenate, thiocarbonate and sulphidic) can be determined ) by heating the sample at 95-lOO C with about 1 N sodium hydroxide for 30 min in the absence of oxygen. By this treatment all the sulphur present is transformed into sulphides, and the anodic wave of sulphide ions is recorded. Elemental sulphur can be determined if the bound sulphur is removed by treating the fibre at 70°C with 10 per cent sulphuric acid for 30 min. 

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