Formation of unexpected selenium-rich compounds by selenation of the very bulky (PhMe2Si)(3)CLi: s-Tetraselenane, a novel polyseleno heterocycle

摘要

The reaction of the highly crowded trisilylmethyllithium compound (PhMe2Si)(3)CLi with elemental selenium resulted in a variety of products, among them the triselane [(PhMe2-Si)(2)CSe](2)Se, the unexpected diselane [(PhMe2Si)(2)HCSe](2) and the novel heterocycle [(PhMe2Si)(2)CSeSe](2). The constitution of the latter could be elucidated from the NMR spectroscopic data and was confirmed by the crystal structure which displays the C2Se4 cycle in the twist form. Calculations were performed for the chair and twist conformers of the heterocycles [(H3Si)(2)CXX](2) (X = O, S, Se, Te, Po).