Synthesis, mol-ecular and crystal structure of [(NH 2 ) 2 CSSC(NH 2 ) 2 ] 2 [RuBr 6 ]Br 2 ·3H 2 O.

The title compound, bis-[di-thio-bis-(formamidinium)] hexa-bromido-ruthenium dibromide trihydrate, [(NH ₂ ) ₂ CSSC(NH ₂ ) ₂ ] ₂ [RuBr ₆ ]Br ₂ ·3H ₂ O, crystallizes in the ortho-rhom-bic system, space group Cmcm , Z = 4. The [RuBr ₆ ] ^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 H ₂ O mol-ecules, Br ^- ions, and NH ₂ 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 [(NH ₂ ) ₂ CSSC(NH ₂ ) 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 NH ₂ 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.
(© Rudnitskaya et al. 2024.)