trithiazyl trichloride
{{Chembox
| ImageFile1 = ThiazylchlorideTrimer.svg
| ImageSize1 =
| ImageFile2 =30558-ICSD.png
| ImageSize2 =
| ImageAlt =
| IUPACName =
| OtherNames = thionitrosyl chloride
|Section1={{Chembox Identifiers
| index_label= trimer
| index1_label= monomer
| CASNo = 5964-00-1
| CASNo1 = 17178-58-4
| ChemSpiderID = 9271996
| ChemSpiderID1 = 123637
| DTXSID1 = DTXSID70938043
| PubChem = 11096854
| PubChem1 = 140196
| SMILES = ClS1=NS(Cl)=NS(Cl)=N1
| SMILES1 = N#SCl
| StdInChI = InChI=1S/Cl3N3S3/c1-7-4-8(2)6-9(3)5-7
| StdInChIKey = QBQMTUMJJWPFDJ-UHFFFAOYSA-N
| InChI1=1S/ClNS/c1-3-2
| InChIKey1 = FWVIYFTZAHMHIO-UHFFFAOYSA-N
}}
|Section2={{Chembox Properties
| Formula = {{chem2|(NSCl)3}}
| N=3|Cl=3|S=3
| Appearance = white solid
| Density =
| MeltingPtC = 168
| BoilingPt =
| Solubility = }}
|Section3={{Chembox Hazards
| MainHazards =
| FlashPt =
| AutoignitionPt = }}
}}
Trithiazyl trichloride is the inorganic compound with the formula {{chem2|(NSCl)3}}. A white 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 {{chem2|S3N3}} core. The molecule has C3v symmetry. The {{chem2|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 to the NSCl connectivity, nitrosyl chloride has the connectivity ONCl.
Synthesis and reactions
Trithiazyl trichloride is obtained by chlorination of tetrasulfur tetranitride or thiazyl fluoride monomer:
:{{chem2|3 S4N4 + 6 Cl2 → 4 (NSCl)3}}
:{{chem2|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.
:{{chem2|(\sN\dS(\sCl)\s)3 → 3 N\tS\sCl}}
In N≡S−Cl, chlorine is bonded to sulfur, in contrast to nitrosyl chloride O=N–Cl, where chlorine is bonded to nitrogen. In contrast, with six fewer electrons, cyanuric chloride is a planar ring.
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:{{Greenwood&Earnshaw2nd}}
: {{chem2|SNCl + S + SbCl5 -> [NS2]SbCl6}}
It reacts with nitriles to dithiadiazolium chlorides:
:{{chem2|6 RCN + 4 (NSCl)3 → 6 [RCN2S2]+Cl- + 3 Cl2 + 3 N2}}
Sulfur trioxide successively oxidizes the compound at the sulfur atoms to {{chem2|(NSOCl)3}},{{cite book|title=Sulfur in Organic and Inorganic Chemistry|volume=1|editor-first=Alexander|editor-last=Senning|year=1971|publisher=Marcel Dekker|location=New York|lccn=70-154612|isbn=0-8247-1615-9|first=H. W.|last=Roesky|chapter=The Sulfur–Nitrogen Bond|pages=20–23}} which exists as stereoisomers.