Tin−Chalcogen Double-Bond Compounds, Stannanethione and Stannaneselone: Synthesis, Structure, and Reactivities

The first isolation of diarylstannanethione (tin−sulfur double-bond compound) and diarylstannaneselone (tin−selenium double-bond compound), Tbt(Ditp)SnX (Tbt = 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl; Ditp = 2,2‘ ‘-diisopropyl-m-terphenyl-2‘-yl; X = S and Se) was accomplished by dechalcogenation
of the corresponding highly hindered tetrachalcogenastannolanes, Tbt(Ditp)SnX4. The 119Sn NMR of
stannanethione, Tbt(Ditp)SnS, and stannaneselone, Tbt(Ditp)SnSe, showed only one low-field broad
signal at 531 and 440 ppm, respectively, characteristic of a tricoordinated tin, and hence, the stannanethione
and stannaneselone display an intrinsic nature of tin−chalcogen double-bond compounds. The X-ray
crystallographic analysis of the isolated stannaneselone, Tbt(Ditp)SnSe 5a, revealed a completely trigonal
geometry around the central tin with a remarkably short Sn−Se bond length, indicative of structural similarity
to a ketone.