Reactivity of Zinc Thiolate Bonds: Oxidative Organopolysulfide Formation and S3 Insertion

Inorg Chem. 2019 Aug 19;58(16):10501-10507. doi: 10.1021/acs.inorgchem.9b01074. Epub 2019 Jun 18.

Abstract

Zinc thiolate bonds are intriguing targets of study because of their redox noninnocence and prevalence in bioinorganic sites. A five-coordinate zinc dithiolate complex [Et4N]2[LZn] (H4L = N,N'-di(2-sulfhydrylphenyl)-pyridine-2,6-dicarboxamide) was synthesized to study the oxidative reactivity of zinc thiolate bonds. Multiple chemically reversible reactions of the zinc thiolate bonds were identified. Oxidation of [Et4N]2[LZn] with iodine resulted in structural rearrangement to a bimetallic disulfide-bridged complex. In contrast, the addition of elemental sulfur to [Et4N]2[LZn] resulted in the insertion of a neutral S3 fragment into the Zn-thiolate bond to selectively form an unusual monometallic tetrasulfanido complex. When oxidized, this tetrasulfanido compound rearranged to form a bimetallic trisulfide-bridged complex. The observed diversity of zinc thiolate reactivity, particularly with sulfur, is likely important in biological contexts.

MeSH terms

  • Coordination Complexes / chemistry*
  • Models, Molecular
  • Molecular Structure
  • Oxidation-Reduction
  • Sulfhydryl Compounds / chemistry*
  • Sulfides / chemistry*
  • Sulfur / chemistry*
  • Zinc / chemistry*

Substances

  • Coordination Complexes
  • Sulfhydryl Compounds
  • Sulfides
  • Sulfur
  • Zinc