Chemistry:Trithiazyl trichloride

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Trithiazyl trichloride
ThiazylchlorideTrimer.svg
30558-ICSD.png
Names
Other names
thionitrosyl chloride
Identifiers
3D model (JSmol)
ChemSpider
Properties
(NSCl)
3
Molar mass 244.55 g·mol−1
Appearance white solid
Melting point 168 °C (334 °F; 441 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Trithiazyl trichloride is the inorganic compound with the formula (NSCl)
3
. A white solid, it is a precursor to other sulfur nitrides,[1] 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 S
3
N
3
core. The molecule has C3v symmetry. The S
3
N
3
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.[2][3]

Synthesis and reactions

Trithiazyl trichloride is obtained by chlorination of tetrasulfur tetranitride:

3 S
4
N
4
+ 6 Cl
2
→ 4 (NSCl)
3

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. In contrast, with six fewer electrons, cyanuric chloride is a planar ring.

Alkoxide or silver salts displace the chlorides:[4]

(-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:[5]

SNCl + S + SbCl
5
→ [NS
2
]SbCl
6

It reacts with nitriles to dithiadiazolium chlorides:[2]

6 RCN + 4 (NSCl)
3
→ 6 [RCN
2
S
2
]+
Cl
+ 3 Cl
2
+ 3 N
2

The compound oxidizes to the S(VI) compound (NSOCl)
3
, which exists as isomers.

References

  1. Jolly, William L.; Maguire, Keith D. (1967). "Sulfur Nitrogen Chlorides". Inorganic Syntheses IX: 102. doi:10.1002/9780470132401.ch27. ISBN 978-0-470-13240-1. 
  2. 2.0 2.1 Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8. 
  3. Wiegers, G. A.; Vos, A. (1966). "The Crystal Structures of Two Sulfur-Nitrogen Compounds with (S-N)3 Rings. II. Trithiazylchloride, (NSCl)3, at -130 C". Acta Crystallographica 20 (2): 192. doi:10.1107/s0365110x66000410. 
  4. Rawson, Jeremy M.; Banister, Arthur J.; Lavender, Ian (1995). "The Chemistry of Dithiadiazolylium and Dithiadiazolyl Rings". Adv. Heterocyc. Chem. 62: 146-147. doi:10.1016/S0065-2725(08)60422-5. 
  5. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.