The syntheses and molecular structures, as determined by single-crystal X-ray diffraction analysis, of the first intramolecularly [4ϩ2]-coordinated tetraorganolead compound {4-t-Bu-2,6-[P(O)(OEt) 2 ] 2 C 6 H 2 }PbPh 3 (2) and the triphenyllead chloride adduct of the first intramolecularly coordinated benzoxaphosphaplumbole {[1(Pb),3(P)-Pb(Ph) 2 OP(O)(OEt)-5-t-Bu-7-P(O)-(OEt) 2 ]C 6 H 2 ·Ph 3 PbCl} (3a) are reported. The reaction of 2 with [Ph 3 C] ϩ [PF 6 ] Ϫ and p-MeC 6 H 4 SO 3 H, respectively, provides the