Explosive antimony is an allotrope of the chemical element antimony that is so sensitive to shocks that it explodes when scratched or subjected to sudden heating. The allotrope was first described in 1855.
Chemists form the allotrope through electrolysis of a concentrated solution of antimony trichloride in hydrochloric acid, which forms an amorphous glass. This glass contains significant amounts of halogen impurity at its boundaries.
When it explodes the allotrope releases 24 calories (100 J) of energy per gram. White fumes of antimony trichloride are produced and the elemental antimony reverts to its metallic form.
- Allan C. Topp (1939). Studies on Explosive Antimony and Antimony Tetrachloride Solutions. Dalhousie University. Retrieved 2016-11-21.
N.C. Norman (1997). Chemistry of Arsenic, Antimony and Bismuth. Springer Science & Business Media. p. 50. ISBN 9780751403893. Retrieved 2016-11-21.
Another possible allotrope, known as explosive antimony, has been reported which is produced by electrolysis of antimony chloride, iodide or bromide and is believed to be in a strained amorphous state.
Otfried Madelung (2012). Semiconductors: Data Handbook. Springer Science & Business Media. p. 408. ISBN 9783642188657. Retrieved 2016-11-21.
Explosive Antimony is only metastable and transforms into metallic antimony during mechanical stress and heating. Explosive Antimony is probably not an allotropic form, but a mixed polymer.
- Egon Wiberg, Nils Wiberg (2001). Inorganic Chemistry. Academic Press. p. 758. ISBN 9780123526519. Retrieved 2016-11-21.
- Bernard Martel (2004). Chemical Risk Analysis: A Practical Handbook. Butterworth-Heinemann. ISBN 9780080529042. Retrieved 2016-11-21.
James H. Walton Jr. (July 1913). "Suspended changes in Nature". Popular Science. p. 31. Retrieved 2016-11-21.
We are indebted to the investigations of Professor Cohen for a more striking example of a metastable metal, that of the " explosive " antimony. By passing an electric current through a solution of antimony chloride this metal may be deposited in the form of a thick metallic coating.
C.C. Coffin, Stuart Johnston (1934-10-01). "Studies on Explosive Antimony. I. The Microscopy of Polished Surfaces". Proceedings of the Royal Society of London. JSTOR 2935608.
- C.C. Coffin (1935-10-15). "Studies on Explosive Antimony. II. Its Structure, Electrical Conductivity, and Rate of Crystallization" (PDF). Proceedings of the Royal Society of London. pp. 47–63. Retrieved 2016-11-21.
F. M. Aymerich, A. Delunas (1975-09-16). "On the explosive semiconductor-semimetal transition of antimony". Physica Status Solidi. doi:10.1002/pssa.2210310118.
The energy released by this transition, is measured to be 24 cal per gram of amorphous Sb and is shown to be related to a variation of the mass density and of the conductivity behaviour of Sb going from one configuration to the other. A simple theoretical model is outlined which quite satisfactory gives the gross features of the free-energy diagram of the above transition, although more deep investigation is needed to account for the energy balance of it.