Tungsten phenylimido complex

Studies of the chemistry of phenylimido rhenium complexes have normally employed Re(NPh)Cl3(PPh3)2 as the starting material because of its easy preparation from aniline and the readily available compound ReOClj(PPh3)2. Tungsten imido complexes cannot be prepared similarly. The lack of good preparative methods leading to suitable starting materials has limited studies with this metal. 

Detailed below are procedures for preparing phenylimido tetrachloro complexes of tungsten and iheniumfVI) that are useful materials for further syntheses. ... 

Petroleum ether (100 mL) is added with a syringe to tetrachlorobis(l, 1-di-methylethanamine)bis[( 1,1 -dimethylethyl)imidobis(phenylimido)ditungsten-(VI) (2g, 2 mmol) contained in a 2S0-mL two-neck round-bottomed flask fitted with a gas inlet tap and a rubber serum cap. A solution of trimethyl phosphine (1.2 mL, 10.9 mmol) in petroleum ether (40 mL) in a 100-mL two-necked round-bottomed flask fitted with gas inlet tap and rubber septum is transferred to the suspension of the tungsten complex in petroleum ether. The serum cap is replaced by a greased glass stopper, and the mixture is stirred for at least 24 h. The dark red complex is removed by filtering, washed twice with petroleum ether (30 mL), and dried under vacuum. Yield 2.1 g (91%). 

---