Acetone peroxide or commonly called TATP is an organic peroxide and acts as a high explosive. It is highly susceptible to heat, friction, and shock. For its instability, it has been called the "Mother of Satan". Also known as "peroxyacetone", acetone peroxide most commonly refers to the cyclic trimer TCAP (tri-cyclic acetone peroxide, or tri-cyclo), also called triacetone triperoxide (TATP), obtained by a reaction between hydrogen peroxide and acetone in an acid-catalyzed nucleophilic addition. The cyclic dimer (C6H12O4) and open monomer and dimer are also formed, but under proper conditions the cyclic trimer is the primary product.

TCAP generally burns when ignited, unconfined, in quantities less than about 2 grams. More than 2 grams will usually detonate when ignited; smaller quantities might detonate when even slightly confined. Completely dry TCAP is much more prone to detonation than the fresh product still wetted with water or acetone.

Acetone peroxide was used as the explosive in the the July 2005 London bombings. The 7 July 2005 London bombings were a series of coordinated terrorist bomb blasts that hit London's public transport system during the morning rush hour. At 8:50 a.m., three bombs exploded within fifty seconds of each other on three London Underground trains. A fourth bomb exploded on a bus nearly an hour later at 9:47 a.m. in Tavistock Square. The bombings killed 52 commuters and the four suicide bombers, injured 700, and caused a severe day-long disruption of the city's transport and mobile telecommunications infrastructure. On 21 July 2005, four attempted bomb attacks disrupted part of London's public transport system two weeks after the 7 July 2005 London bombings. The explosions occurred around midday at Shepherd's Bush, Warren Street and Oval stations on London Underground, and on a bus in Shoreditch. It has been reported that a fifth bomber dumped his device without attempting to set it off. Richard Reid, who attempted to down American Airlines Flight 63 with a bomb concealed in his shoe, employed a device containing plastic explosive with a TATP trigger.

Formal Chemical Name (IUPAC)
3,3,6,6,9,9-hexamethyl-1,2,4,5,7,8-hexaoxacyclononane

References

http://en.wikipedia.org/wiki/Acetone_peroxide

http://news.bbc.co.uk/1/hi/uk/6435195.stm