Potassium Salts Thiocarbonate

Sodium ferro-heptanitroso sulphide, NaFe4(NO)7S3.2H20, may be obtained in a similar manner to the potassium salt by boiling a solution of sodium ferro-dinitroso thiosulphate, as also by the action of sodium nitrite and sulphide solutions upon ferrous sulphate. In this latter reaction the sodium sulphide may be replaced by sodium thiocarbonate, Na2CS3. 

A particular case is the use of a hydrogen sulfide salt instead of the thiol, to effect the fragmentation. Treatment of the thiocarbonate derived from cysteine with 2 equiv of potassium hydrogensulfide in methanol results in the formation of the potassium salt of thiocysteine in 85% yield (eq 2). ... 

Under certain conditions thiocarbonates behave like simple sulphides thus, benzoyl chloride and a thiocarbonate in equimoleeular proportions yield benzoyl disulphide, which substance is also formed by the interaction of benzoyl chloride and potassium hydrogen sulphide followed by oxidation. The complex salts of the thiocarbonates are more stable than the simple salts. 

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