Sulfur transfer reactions of a zinc tetrasulfanido complex†
A zinc tetrasulfanido complex supported by a bis(carboxamide)pyridine ligand framework has been synthesized by the insertion of elemental sulfur into the zinc–S(thiolate) bond of a zinc dithiolate complex ([LZn]2−). This paper reports on sulfur transfer reactions of this polysulfanido complex (2−) and compares this behavior to known reactions of metal polysulfido complexes. Complex 2− was demonstrated to be in exchange with [LZn]2− and free elemental sulfur in solution. Although triphenylphosphine abstracts sulfur from 2− to form [LZn]2−, complex [LZn]2− can abstract sulfur from the zinc polysulfido complex (TMEDA)ZnS6 (TMEDA = N,N,N′,N′-tetramethylethylenediamine). The tetrasulfanido complex 2− can also transfer sulfur to dimethyl acetylenedicarboxylate to form a zinc dithiolene complex. These studies demonstrate that the zinc complex with a tetrasulfanido moiety can undergo similar reactions as metal complexes with purely inorganic polysulfido groups, although the final metal-containing products are different.