SYNTHESIS AND STRUCTURE OF 1,2,3,4,5-TETRATHIAPLUMBOLANES, THE FIRST STABLE PB-CONTAINING CYCLIC POLYSULFIDES

The first examples of Pb-containing cyclic tetrasulfides, R(Tip)PbS4 [ 4 (R=Tip) and 5 (R=Tbt); Tip=2,4,6-triisopropylphenyl, Tbt=2,4,6-tris[ bis(trimethylsilyl)methyl]phenyl], were synthesized and isolated as st able crystalline compounds by the sulfurization of the corresponding o vercrowded diarylplumbylenes, Tip(2)Pb: (6) and Tbt(Tip)Pb: (10). Mole cular structures of 4 and 5 were determined by X-ray crystallographic analysis. Desulfurization reactions of the tetrathiaplumbolanes 4 and 5 leading to the formation of plumbanethiones R(Tip)Pb=S, novel lead-s ulfur double bond compounds, are also described.