Dd. Vanderlende et al., SYNTHESIS OF A SQUARE PYRAMIDAL TUNGSTEN(VI) ALKYLIDENE COMPLEX WITH A BIS(AMIDE) CHELATE LIGAND, Organometallics, 13(9), 1994, pp. 3378-3380
Reaction of Li-2[(NSiMe(3))(2)C6H4] with W(NPh)-Cl-4(OEt(2)) yields W(
NPh)Cl-2[(NSiMe(3))(2)C6H4], 3. Compound 3 can be alkylated to give th
e corresponding dialkyls, W(NPh)R(2)[(NSiMe(3))(2)C6H4]. W(NPh)(CH(2)C
Me(3))(2)[(NSiMe(3))(2)C6H4], 4a, can be heated in the presence of exc
ess PMe(3) to give the new alkylidene complex W(NPh)(CHCMe(3))[(NSiMe(
3))(2)C6H4], 5. The X-ray structure of 5 reveals that 5 adops a unique
square pyramidal structure with the alkylidene carbon in teh apical p
osition.