Sulfur transfer reactions of a zinc tetrasulfanido complex

Abstract

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 ([1]²⁻) and compares this behavior to known reactions of metal polysulfido complexes. Complex [1]²⁻ was demonstrated to be in exchange with [LZn]²⁻ and free elemental sulfur in solution. Although triphenylphosphine abstracts sulfur from [1]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 [1]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.