Formation and Identification of Bis[bis(trimethylsilyl)amino]triand tetrachalcogenides

Abstract

The reaction of (Me3Si)2NLi with SCl2 and elemental sulfur or with Se2Cl2 and elemental selenium leads to the formation of mixtures of bis[bis(trimethylsilyl)amino]suIfides and selenides [(Me3Si)2N]2Ex (E = S or Se; x = 1 - 4 ). The reaction products were identified by mass spectroscopy as well as by 77Se and 13C NMR spectroscopy. The reaction of (Me3Si)2NH with S2Cl2 produces [(Me3Si)2N]2S3 as the main product with only traces of other aminosulfides. [(Me3Si)2N]2S3 was purified by distillation under reduced pressure and identified by elem ental analysis, mass spectroscopy, and by 1H, 13C, and 14N NMR spectroscopy. The successful cyclocondensation reaction of [(Me3Si)2N]2S3 with SCl2 and SO2Cl2 produces S4N2 in 72% yield and provides further verification of the identity of bis[bis(trimethylsilyl)amino]trisulfide. While the analogous reaction of (Me3Si)2NH with Se2Cl2 also leads to the formation of [(Me3Si)2N]2Se3 (48 mol %) as the main product, the reaction mixture contains [(Me3Si)2N]2Se2 and [(Me3Si)2N]2Se4 in significant amounts (17 and 35 mol %, respectively). Attempts to purify the mixture by distillation under reduced pressure resulted only in the formation of a 83:17 mixture of [(Me3Si)2N]2Se2 and [(Me3Si)2N]2Se3.