cis-RuCl2(DMSO)4

 

Inorganic Syntheses Vol 35, p. 148

4.20g of RuCl3.xH2O (x~3) and 99% EtOH 100mL (non-denatured) was refluxed gently on a 95C oil bath under air-cooled condenser opened to air, for 3 hours. The obtained dark greenish solution was filtered through a medium porosity fritted funnel, to remove some insoluble particles, the filtrates were evaporated on rotovap in a 300mL flask. The dark honey-like residue was combined with DMSO 16mL. The mixture was stirred on a 150C oil bath under air-cooled condenser opened to air, for 2 hours. During this time the reaction mixture color changed to orange-red and then yellow precipitate formed. After 2 hours, the reaction mixture was allowed to cool to room temperature, the obtained slurry was gradually diluted with acetone 120mL and the mixture was allowed to crystallize overnight (14 hours). The precipitated yellow heavy crystalline solid was collected by filtration, rinsed thoroughly with acetone, dried by suction and then on highvac.

Y=6.58g (85% th) of a yellow crystalline solid.

1H(D2O, 400 MHz, a 10 minute-old sample): 3.46(s,6H), 3.44(s, 6H), 3.35(s, 6H), 2.69(s, 6H)

Note 1: This preparation works best when performed under air. Common Alihn reflux condenser unconnected to water source was used for the purpose.

Note 2: The oxygen-bound axial DMSO ligand solvolyzes readily, the D2O-NMR spectra  actually belongs to the aqua complex and free 1 equiv of DMSO formed in situ. The NMR sample in D2O is not stable, some new peaks start appearing after 20 minutes.