Trithiazyl trichloride
Chemical compound
From Wikipedia, the free encyclopedia
Trithiazyl trichloride is the inorganic compound with the formula (NSCl)3. A pale yellow solid, it is a precursor to other sulfur nitrides,[1] but has no commercial applications.
| |
 | |
| Names | |
|---|---|
| Other names
thionitrosyl chloride | |
| Identifiers | |
| |
3D model (JSmol) |
|
| ChemSpider | |
PubChem CID |
|
CompTox Dashboard (EPA) |
|
| |
| |
| Properties[1][2] | |
| (NSCl)3 | |
| Molar mass | 244.55 g·mol−1 |
| Appearance | pale yellow solid |
| Melting point | Decomposes at 91 °C (196 °F; 364 K) |
| Solubility | soluble in CCl4, CS2, benzene, toluene, THF |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
| |
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 S3N3 core. The molecule has C3v symmetry. The S3N3 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.[3][4]
Synthesis and reactions
Trithiazyl trichloride is obtained by chlorination of tetrasulfur tetranitride or thiazyl fluoride monomer:[5]
- 3 S4N4 + 6 Cl2 → 4 (NSCl)3
- 3 FSN + 3 Cl2 → (NSCl)3 + 3 ClF
At 100 °C in vacuum, thiazyl chloride trimer undergoes cracking to thiazyl chloride monomer, which is a green gas.
- (−N=S(−Cl)−)3 → 3 N≡S−Cl
In N≡S−Cl, chlorine is bonded to sulfur, in contrast to nitrosyl chloride O=N–Cl, where chlorine is bonded to nitrogen.[3][4]
Alkoxide or silver salts displace the chlorides:[6]
- (–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:[7]
- SNCl + S + SbCl5 → [NS2]SbCl6
It reacts with nitriles to dithiadiazolium chlorides:[3]
- 6 RCN + 4 (NSCl)3 → 6 [RCN2S2]+Cl− + 3 Cl2 + 3 N2
Sulfur trioxide successively oxidizes the compound at the sulfur atoms to (NSOCl)3.[5] 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.[8]