Chemistry:Dithionitronium hexafluoroarsenate

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Dithionitronium hexafluoroarsenate
NS2AsF6.svg
Identifiers
3D model (JSmol)
ChemSpider
Properties
AsF6N2S
Molar mass 248.99 g·mol−1
Appearance yellow solid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Dithionitronium hexafloroarsenate is the inorganic compound with the formula [SN
2
]AsF
6
. It is the hexafluoroarsenate (AsF
6
) salt of S=N=S+. The cation is of interest as the sulfur analogue of nitronium (NO+
2
). Hexafloroarsenate is a weakly coordinating anion. According to X-ray crystallography, S=N=S+ is linear with S-N distances of 146 picometers.[1]

Synthesis and reactions

Dithionitronium hexafluoroarsenate is prepared from thiazyl chloride using silver hexafluoroarsenate.[2] The hexachloroantimonate salt can be prepared by treating thiazyl chloride with sulfur in the presence of antimony pentachloride according to this idealized equation:

SNCl + S + SbCl
5
→ [NS
2
]SbCl
6

The dithionitronium cation reacts with nitriles to give dithiadiazolium salts:[3]

[NS
2
]+
+ RCN → [RCN
2
S
2
]+

Addition to alkynes gives dithiazolium salts:

[NS
2
]+
+ R
2
C
2
→ [(RC)
2
NS
2
]+

References

  1. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8. 
  2. Ayres, Bryan; Banister, Arthur J.; Coates, Philip D.; Hansford, Michael I.; Rawson, Jeremy M.; Rickard, Clifton E. F.; Hursthouse, Michael B.; Malik, K. M. Abdul et al. (1992). "A General Route to N(SCl)2+ and SNS+ Salts". Journal of the Chemical Society, Dalton Transactions (21): 3097. doi:10.1039/DT9920003097. 
  3. Rawson, Jeremy M.; Banister, Arthur J.; Lavender, Ian (1995). "The Chemistry of Dithiadiazolylium and Dithiadiazolyl Rings". Adv. Heterocyc. Chem. 62. doi:10.1016/S0065-2725(08)60422-5.