Synthesis and structure of 1,2,3,4,5-tetrachalcogenastannolanes

Article abstract of DOI:10.1021/om00028a059

Novel cyclic polychalcogenides, 1,2,3,4,5-tetrathia- and tetraselenastannolanes [Tb(R)SnY₄ (Y = S, Se; Tb = 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl; R = mesityl or 2,4,6-triisopropylphenyl)], have been synthesized by two routes, i.e., (a) the reaction of dihydrostannanes Tb(R)SnH₂ with sulfur or selenium and (b) the lithiation of dihydrostannanes Tb(R)SnH₂ or dichlorostannanes Tb(R)SnCl₂ with t-BuLi followed by reaction with sulfur or selenium. All the tetrachalcogenastannolanes have been characterized by ¹H and ¹³C NMR and elemental analysis. In addition, Tb(MeS)SnS₄ (7b) and Tb(MeS)SnSe₄ (8b) have been subjected to single-crystal X-ray diffraction analysis. Both five-membered 7b and 8b have distorted envelope conformation, the former of which is slightly more distorted. The reason for the exclusive formation of five-membered polychalcogenides has been discussed on the basis of the X-ray structural analysis and ab initio calculations for the model ring system H₂SiS_n (n = 2-6).