Synthesis, mol-ecular and crystal structure of [(NH2)2CSSC(NH2)2]2[RuBr6]Br2·3H2O

Abstract

The title compound, bis-[di-thio-bis-(formamidinium)] hexa-bromido-ruthenium dibromide trihydrate, [(NH₂)₂CSSC(NH₂)₂]₂[RuBr₆]Br₂·3H₂O, crystallizes in the ortho-rhom-bic system, space group Cmcm, Z = 4. The [RuBr₆]^2- anionic complex has an octa-hedral structure. The Ru-Br distances fall in the range 2.4779 (4)-2.4890 (4) Å. The S-S and C-S distances are 2.0282 (12) and 1.783 (2) Å, respectively. The H₂O mol-ecules, Br^- ions, and NH₂ groups of the cation are linked by hydrogen bonds. The conformation of the cation is consolidated by intra-molecular O-H⋯Br, O-H⋯O, N-H⋯Br and N-H⋯O hydrogen bonds. The [(NH₂)₂CSSC(NH₂)₂]²⁺ cations form a hydrogen-bonded system involving the Br ^- ions and the water mol-ecules. Two Br ^- anions form four hydrogen bonds, each with the NH₂ groups of two cations, thus linking the cations into a ring. The rings are connected by water mol-ecules, forming N-H⋯O-H⋯Br hydrogen bonds.

Keywords: anions; cations; crystal structure; ruthenium halido complexes; αα′-(di­thio­bis­formamidinium) cation.