Heptasulfur imide

Heptasulfur imide is the inorganic compound with the formula S7NH. It is a pale yellow solid that is, like elemental sulfur, highly soluble in carbon disulfide. The compound, which is only of academic interest, is representative of a family of sulfur imides Sx(NH)y.

Heptasulfur imide
Skeletal formula of heptasulfur imide
Ball-and-stick model of the heptasulfur imide molecule
3D model (JSmol)
Appearance pale yellow solid
Density 2.01 g/cm3
Melting point 113.5 °C (236.3 °F; 386.6 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Synthesis and structureEdit

It is prepared by reaction of disulfur dichloride with ammonia,[1] although other methods have been developed.[2] Together with S7NH, the reaction also produces three isomers of S6(NH)2 and two isomers of S5(NH)3.

It is an analogue of S8, with one S replaced by NH. The S2NH center is almost planar,[3] suggesting that the amine is nonbasic.


  1. ^ Becke-Goehring, Margot; Fluck, Ekkehard "Heptasulfur imide" Inorganic Syntheses 1966, vol. 8, 103-5. doi:10.1002/9780470132395.ch26
  2. ^ Bojes, J.; Chivers, T.; Drummond, I. "Heptathiazocine(heptasulfurimide) and tetrabutylammonium tetrathionitrate" Inorganic Syntheses (1978), 18, 203-6. doi:10.1002/9780470132494.ch36
  3. ^ Hecht, H. J.; Reinhardt, R.; Steudel, R.; Bradaczek, H. "Redetermination of the crystal and molecular structure of heptasulfur imide, S7NH" Zeitschrift für Anorganische und Allgemeine Chemie 1976, vol. 426, pp. 43-8. doi:10.1002/zaac.19764260106