Thionitrosyl Complexes of Ruthenium II

Trichloro(thionitrosyl)bis(triphenylphosphine)ruthenium(II)was previously prepared by the reaction of trithiazyl trichloride in THF with RuCL xHjO and triphenylphosphine in absolute ethanol. The product crystallizes over a period of several hours, and the yield is very poor. The same complex can be prepared from dichlorotris(triphenylphosphine)ruthenium(II) in CH2CI2 and trithiazyl trichloride in tetrahydrofuran (THF) in a better yield and in less time. 

After 2.87 g (3 mmol) of RuCl3(PPh3)2 is placed in a 250-mL round-bottomed flask, 75 mL of CH2CI2 is added, followed by the addition of a solution of (NSC1)3 (0.5 g, 2mmol) in 30 mL of dry THF. The mixture is stirred for 30 min and 100 mL of methanol is added. Ru(NS)Cl3(PPh3)2 precipitates as shining brown crystals. The precipitation is completed within 10-15 min. The 

Trichlorothionitrosylbis(triphenylphosphine)ruthenium(ll) is a reddish brown crystalline substance, which melts at 176-178° in air. The IR spectrum of the compound shows a strong absorption both in KBr pellet as well as in Nujol mull band due to v(NS) at 1310 cm . The compound is sparingly soluble in dichloromethane, chloroform, and benzene but insoluble in alcohol, ether, and hexane. The compound is stable in air for an indefinite period. The X-ray diffraction pattern of powdered Ru(NS)Cl3(PPh3)2 shows it to be isomorphic with Ru(NO)Cl3(PPh3)2.  

Solutions of 1.7 g (2 mmol) of trichlorobis(triphenylarsine) monomethanol ruthenium(III) in 40mL of CH2CI2 and of 1.0g (4 mmol) of trithiazyl trichloride in 30mL of dry THF are mixed together rapidly. The initial 

---