Group 11 metals, dithiocarbamate applications

Evolved gas applications are widespread and diverse. Coordination chemistry has been considerably enhanced by thermal analysis studies of a wide range of metal complexes. The emphasis of these studies has been to derive thermal decomposition mechanisms for such metal complexes. Prior to the development of EGA, such reported mechanisms were suspect because the volatile decomposition products and the solid intermediates were, in general, not identified directly but characterized indirectly on the basis of mass loss data. This procedure is flawed when multiple gaseous decomposition products and nonstoichiometiic intermediates are involved. The thermal analysis of one such group of metal complexes, the metal dithiocarbamates, has been extensively studied and reviewed by Hill and Magee and these are definitive studies in this field. 

Various types of monomers have been used to introduce cure-sites into polyacrylic elastomers. Polyacrylic elastomers containing active chloride, epoxy, and carboxyl groups as active cure-sites have been developed for industrial applications. Polyacrylic elastomers which contain epoxy groups are vulcanized with ammonium salts and dithiocarbamate salts, whereas elastomers which contain active chloride are vulcanized with sulfur-metal soap, organic amines, etc. 

The dithiocarbamate chemistry of the group 12 (11B) elements is well developed, with applications in the areas of analytical chemistry, agriculture, rubber vulcanization, and as molecular precursors to metal sulfides. As expected, their chemistry is constrained to the - -2 oxidation state and it is the bis(dithiocarbamate) complexes [M(S2CNR2)2], which are the most common, being first prepared in 1907 (2). 

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