Sulfurization, plumbylene

X-ray crystallographic analysis reveals that plumbylene 141 exists as a monomer, and there is no intermolecular interaction between the lead and sulfur atoms,643 while other heteroatom-substituted plumbylenes so far known exist as a heteroatom-bridged cyclic oligomer.65... 

Recently, however, Tokitoh and co-workers " °° reported a versatile reactivity of Tbt-substituted plumbylenes 182a-d, that is, insertion reactions with alkyl halides, diphenyl dichalcogenides, bromine abstraction from carbon tetrabro-mide, and sulfurization with elemental sulfur as shown in Scheme 14.83. 

Note also the reactivity of the heteroleptic plumbylene 174 toward carbon disulfide. Treatment of 174 with excess amount of carbon disulfide resulted in a formation of unexpected product, lead(II) bis(aryl trithiocarbonate) (192), as a yellow, air- and moisture-stable solid (Scheme 14.85). The reaction must involve not only the insertion of carbon disulfide into the Pb—S bond, but also the formal insertion of a sulfur atom into the Pb C(Tbt) bond and subsequent insertion of another... 

The reaction of less hindered diarylplumbylenes with elemental sulfur, Sg, gives three different types of Pb-S heterocycles, whereas the reaction of highly crowded diaryl plumbylenes gives only the aryl substituted polysulfides (Scheme 2). 

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