Chalcogen halides

Reactions of ionic or covalent azides with chalcogen halides or, in the case of sulfur, with the elemental chalcogen provide an alternative route to certain chalcogen-nitrogen compounds. Eor example, the reaction of sodium azide with cyclo-Sa in hexamethylphosphoric triamide is a more convenient synthesis of S7NH than the S2CI2 reaction (Section 6.2.1). Moreover, the azide route can be used for the preparation of 50% N-enriched S7NH. 

Scheme 2.2 Reactions of trisilylated benzamidines with chalcogen halides...

Imido chalcogen halides of the type RNEC12 (E=S, Se, Te) provide an interesting illustration of the reluctance of the heavier chalcogens to form -N=E< double bonds. The sulfur derivatives RNSX2 (X=F, Cl) are stable, monomeric compounds. 

The acyclic imidoselenium(II) dihalides Cl Sc[N( Bu)Sc] Cl (57, n 1 58, n = 2) are obtained from the reaction of SeCl2 with tert-butylamine in a 2 3 molar ratio in THF.160 There are no sulfur or tellurium analogues of this class of imido chalcogen halide. 

Acidic chalcogenates Oxide-chalcogenates Halide-chalcogenates... 

The most remarkable of the chalcogen halides is sulfur(Vl) fluoride, SF, which may be prepared directly from the elements. This compound is astoundingly inert to a multitude of diverse reagents. Concentrated... 

Only a few chalcogen halide adducts with oxide halides are known. In the course of a systematic study on exchange reactions of transition metal oxides with SCI2/CI2, paramagnetic [SCla JtMoOCU ] was obtained and characterized (157,241). 

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