Synthesis and properties of polysulphides based on trifunctional metal β-diketonates☆

The reaction of Cr, Al, Co3+ tris-(3-chlorosulphenyl-2,4-pentadionates) with mercury diethyl, ethyl-,buthyl-, and phenyl-magnesium bromides and lithium phenyl results in the formation of soluble thermoplastic coordinated oligomers or three dimensional polymers. With increase in the rigidity of the nucleophile, the ratio of the monosulphide and disulphide bonds is decreased, and the MM of the oligomers is increased correspondingly. The minimum degree of polydispersity is shown by chromium containing oligomers with phenyl substituents on the sulphur atoms. Thermooxidative degradation of the disulphide oligomers takes place consecutively through the stages of splitting off of the organic substituent, sulphur, and an acetylacetonate fragment, and the stability is decreased in the series of oligomers, i.e. aluminium containing>chromium containing, phenyl containing>ethyl group containing.