Synthesis and structure of [(NH2)2CSSC(NH 2)2]2[OsBr6]Br2· 3H2O

The complex [(NH2)2CSSC(NH2) 2]2[OsBr6]Br2· 3H 2O is synthesized by the reaction of K2OsBr6 with thiocarbamide in concentrated HBr and characterized using electronic absorption and IR absorption spectroscopy. Its crystal structure is determined by X-ray diffraction. The crystals are orthorhombic, a = 11.730(2) Å, b = 14.052(3) Å, c = 16.994(3) Å, space group Cmcm, and Z = 4. The [OsBr6]2- anionic complex has an octahedral structure. The Os-Br distances fall in the range 2.483-2.490 Å. The α, α′-dithiobisformamidinium cation is a product of the oxidation of thiocarbamide. The S-S and C-S distances are 2.016 and 1.784 Å, respectively. The H2O molecules, Br-ions, and NH 2 groups of the cation are linked by hydrogen bonds. © 2008 Pleiades Publishing, Ltd.