Ethylene sulphide, polymerization

The anionic polymerization of thiiranes appears to proceed very clearly and in a well defined manner. Living systems have been found and good kinetic measurements have been possible [36]. The base catalysed polymerization of ethylene sulphide (ES) was probably one of the earliest thiirane polymerizations noted. However, the studies have been hindered because the polymer formed is highly crystalline and insoluble. Homogeneous solution studies have not been possible. Propene sulphide (PS) on the other hand gives soluble amorphous polymer and has been amenable to careful study. Indeed the formation of amorphous polypropene sulphide is the major evidence that base catalysed polymerization is ionic and proceeds by the reactions indicated by the equations... 

The redox reactions of metallo phthalocyanine electrodes cause a selective and efficient catalysis for many photochemical and electrochemical reactions at moderate potentials [3,57,70,161,171,172]. The electrons are transported by electronically conductive polymers and also by electron exchange reaction in the oxidizable or reducible groups present in the incorporated polymer. Phthalocyanine and their derivatives have been studied for the catalytic behaviour in the oxidation of acetaldehyde ethylene acetate, iodide and other aldehydes such as benzaldehyde and acrolein [3,57,70,120,231-235]. In the latter cases pyridine was used as an activator. The oxidation reactions are found to follow through a peroxy intermediate. The effectiveness of the catalyst for the reaction depends on the purity, uniformity, stability and turnover number of the phthalocyanine polymer. Oxidative polymerization of phenols to polyoxyphenylenes and thiols to sulphides has also been reported [57,70,120,236-238]. 

Condensation reactions yielding cyclic and/or linear oligosulfides were studied by four research groups [89-93]. In 1863, Husemann [89] prepared an intermediate by condensation of 1,2-dibromoethane with sodium sulfide. By heating he obtained the cyclic dimer, dithiane, as a volatile degradation product. Mansfeld [90] reinvestigated this reaction and interpreted the intermediate as polymer, but he speculatively assigned the formula of a cyclic trimer. Husemann also prepared poly(methylene sulphide) from dibromomethane and sodium sulfide. Furthermore, he performed condensations of dibromomethane and dibromoethane, respectively, with sodium trithiocarbonate, which was easily obtained from sodium sulfide and carbon disulfide. He isolated a five-membered cyclic ethylene trithiocarbonate, but a polymeric methylene trithiocarbonate the molar mass of which remained obscure. 

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