Trithiazyl trichloride is the inorganic compound with the formula . A pale yellow solid, it is a precursor to other sulfur nitrides, but has no commercial applications.
Structure The molecule is a 6-membered ring of alternating nitrogen and sulfur atoms, where each sulfur atom is attached to one chlorine atom by a single bond. The molecule contains alternating single and double bonds in the core. The molecule has C3v symmetry. The core is slightly ruffled structure with S-N distances of 160.5 pm. The S-Cl distances are 208 pm, and the chlorine atoms are mutually cis. The S centers are tetravalent and pyramidal. In contrast, with six fewer electrons, cyanuric chloride is a planar ring.
Synthesis and reactions Trithiazyl trichloride is obtained by chlorination of tetrasulfur tetranitride or thiazyl fluoride monomer:
At 100 °C in vacuum, thiazyl chloride trimer undergoes cracking to thiazyl chloride monomer, which is a green gas.
In N≡S−Cl, chlorine is bonded to sulfur, in contrast to nitrosyl chloride O=N–Cl, where chlorine is bonded to nitrogen.
Alkoxide or silver salts displace the chlorides: (–NS(Cl)–)3 + 3 NaOR → (–NS(OR)–)3 + 3 NaCl (–NS(Cl)–)3 + 3 AgX → (–NS(X)–)3 + 3 AgCl
Treating thiazyl chloride with sulfur in the presence of antimony pentachloride gives dithionitronium hexachloroantimonate:
It reacts with nitriles to dithiadiazolium chlorides:
Sulfur trioxide successively oxidizes the compound at the sulfur atoms to . The latter is also the pyrolysis product of a mixture of phosphorus pentachloride and sulfamic acid. In principle, it exists as stereoisomers, but only one (all chlorides axial) had been isolated by 1979.
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