Chemistry of thiocarboxylates: syntheses and characterization of silver and copper thiocarboxylate complexes, and the structures of [Ph4P][M(SC{O}Me)2] (M = Cu or Ag) and [Et3NH][Ag(SC{O}Ph)2]

Abstract

The bis(thiocarboxylate) complexes of silver(I) and copper(I) namely, [Ph₄P][M(SC{O}Me)₂], (M = Cu 1 or Ag 2) and [Et₃NH][M(SC{O}Ph)₂] (M = Cu 3 or Ag 4) were prepared from the appropriate metal salt, RC{O}S^– anions and the counter ion in the ratio 1∶2∶1. The structures of 1, 2 and 4 were determined by X-ray crystallography. The compounds 1 and 2 are isomorphous and isostructural. In both structures, the metal is bonded to sulfur atoms of two thioacetate ligands to give a near-linear geometry. A crystallographically imposed 2-fold rotational symmetry is present in the anions and the cations. The [Ag(SC{O}Ph)₂]^– anion in 4 also has an approximately-linear SAgS skeleton. One of the S atom interacts weakly with a second silver(I) ion to form a dimer. The N–H hydrogen atom of the Et₃NH⁺ cation is involved in N–H· · ·O hydrogen bonding to a carbonyl oxygen atom of the anion. There is a crystallographic center of symmetry present in this ‘ion-pair dimer’, having a rectangular arrangement of Ag₂S₂ with a T-shaped coordination geometry around the silver atoms. All the compounds decompose under a nitrogen atmosphere to the corresponding metal sulfides according to weight loss observed in TG.