Synthesis, Structure, and Reactivity of Kinetically Stabilized Divalent Organolead Compounds (Plumbylenes)

Abstract

Divalent organolead compounds (plumbylenes; Tip2Pb (6; Tip = 2,4,6-triisopropylphenyl) and Tbt(R)Pb (7a, R = Tbt; 7b, R = Ttm; 7c, R = Tip; 7d, R = Dis; Tbt = 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl, Ttm = 2,4,6-tris[(trimethylsilyl)methyl]phenyl, and Dis = bis(trimethylsilyl)methyl)) were synthesized by taking advantage of kinetic stabilization afforded by bulky substituents and characterized by UV/vis and 207Pb NMR spectroscopy. X-ray structural analysis revealed that plumbylene 7a has a V-shaped, monomeric structure. Reactions of these plumbylenes with methyl iodide, carbon tetrabromide, diphenyl disulfide, diphenyl diselenide, and elemental sulfur are described. New methods for the synthesis of plumbylenes from tetravalent organolead compounds, by reductive debromination of dibromoplumbanes and exhaustive desulfurization of tetrathiaplumbolanes, were developed.