η3-Allyl Coordination at Pb(II)

Allylmagnesium chloride and methyl-propenyl-magnesium bromide were reacted with bulky substituted organolead and organotin halides (Ar*PbBr)(2), (Ar'PbBr)(2), (Ar*SnCl)(2) (Ar* = 2,6-trip(2)C(6)H(3)-, trip = 2,4,6-triisopropylphenyl, Ar' = 2,6-mes(2)C(6)H(3)-, mes = 2,4,6-trimethylphenyl). The allyl ligand coordinates in an eta(3)-coordination mode at organoplumbylene fragments. In the solid state as well as in solution, eta(3)-coordination was characterized by crystal structure analysis and Saunders' isotopic perturbation technique. For the plumbylene Ar*Pb(C3H5), a solid state Pb-207 magic angle spinning (MAS) NMR spectrum could be obtained. The isotropic chemical shift is -435 ppm, and the magnitude of the Pb-207 chemical shift tensor of 7000(500) ppm is among the greatest observed experimentally. The methylallyl ligand coordinated at a plumbylene fragment exhibits two short and one long Pb-C interaction. In reaction with aniline, the allyl ligand reacts as a leaving group to give amidoplumbylenes.