UEBER POLYPLUMBANE. I. ASYMMETRISCH SUBSTITUIERTE DIPLUMBANE

Article abstract of DOI:10.1016/0022-328X(85)80302-8

Diplumbanes Pb2R3R'3 (R,R'=Ph, o-Tol, p-Tol) have been synthesized from R3PbLi and R'PbCl at -60 deg C in THF.Mass, 13C and 207Pb NMR spectra of the products exhibit migrations of R, R' in the transition state (R3PbLi + ClPbR'3) leading to a complex distribution of the substituents (δ(207Pb) with respect to PbMe4 -70 to -95 ppm).The Pb-Pb stretching vibration (100 to 115 cm^-1) couples with a lattice vibration giving rise to a single intensive Raman line.The crystal structure of Pb2Ph3(p-Tol)3 has been determined and refined to R=0.155.Two independent molecules are disordered and have identical distribution of the substituents Ph(p-Tol)2Pb-PbPh2(p-Tol) (distances Pb-Pb 283(2) and 286(1) pm).Products Pb2Ph3(OAc)3 with a Pb-Pb bond, already discussed in the literature, could not be verified.