Copolymerisation of Tiiranes and Carbon

Ethylene sulphide and propylene sulphide have been reported by Soga et ol. [249,250] to copolymerise with carbon disulphide in the presence of catalysts such as diethylzinc, diethylcadmium and mercury bis( -butanethiolatc), yielding poly(alkylene thioether-trithiocarbonate) copolymers (Table 9.4). The content of ethylene trithiocarbonate units in the ethylene sulphide/carbon disulphide copolymer obtained with the most efficient catalyst, mercury bis( -butanethiolate), was in the range 50-70 mol.-% [249]. 

In order to clarify the mechanism, the reaction of carbon disulphide with mercury bis(n-butanethiolate) was studied. On the basis of results obtained, it was suggested that this reaction involved the formation of a coordination complex, followed by the formation of active species containing the Hg-SC(S) bond. Moreover, the cyclic trithiocarbonate, ethylene trithiocarbonate, found to be present in trace amounts in copolymerisation products, was excluded as a possible intermediate for the copolymer formation, since it did not undergo any polymerisation under the given conditions [249], 

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