Researchers at the Technion-Israel Institute of Technology report that they have discovered six new polymorphic crystalline structures of triacetone-triperoxide (TATP), the easy to make but difficult to detect explosive, thought to be used in the July 2005 London bombings and used by terrorists worldwide.
The findings, which were published online in ACS Crystal Growth & Design, will make it easier to detect TATP, even when it is concealed, it is claimed.
TATP was previously believed to have just one crystalline form. However, using methods that include X-ray crystallography (which reveals the arrangement of atoms within a crystal), Prof Ehud Keinan of the Technion Faculty of Chemistry and colleagues have found the explosive can form at least six types of crystals, depending on the conditions during its synthesis and crystallization. The discovery of new forms of the explosive will now make it easier to identify using x-ray and other techniques.
TATP is popular among terrorists around the world for two reasons – it is easy to prepare, difficult to detect. Prof Keinan’s team at the Technion previously developed a device for identifying traces of TATP and other peroxide-based explosives. The Peroxide Explosive Tester (PET), which resembles a three-color ballpoint pen, changes colour when it has been in contact with explosive samples.
Professor Keinan said: “One way to detect certain kinds of explosives is a method called x-ray powder diffraction. Each of these crystals has its own distinct structure, and identifying six, and very possibly more of these polymorphs, is a big step toward more reliable TATP detection.”
