Chalcogen-Nitrogen Halides Containing Two Chalcogens

The reaction of Me3SiNSNSiMc3 with TeCU is an especially fruitful source of chalcogen-nitrogen halides that contain both sulfur and tellurium. The initial product of this reaction is the bicyclic compound 8.17, which is obtained when the reaction is carried out in a 1 2 molar 

The bicyclic compound 8.17 also serves as a source of the five-membered ring 8.20 upon reduction with SbPhs. In contrast to the related S or Se systems, 8.11a and 8.11b, both Cl substituents are attached covalently to Te in 8.20. Reaction of 8.20 with an excess of AsFs in SO2 produces the eight-membered cyclic [Tc2S2N4] dication, which exhibits a Te-Te bond length of 2.88 A (cf. 2.70 A for a Te-Te single bond) and no transannular S S bonding J 

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