Advertisement

If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)

ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.

ENJOY UNLIMITED ACCES TO C&EN

Materials

High-Energy Salts Exhibit Explosive Potential

Energetic Materials: A new family of triazole salts combines a big bang with less of a hair trigger

by Christine Herman
November 3, 2011

Explosive Chemistry
[+]Enlarge
Credit: J. Am. Chem. Soc.
New explosive triazole salts made from 5-nitro-3-trinitromethyl-1H-1,2,4-triazole (top) and 5,5’-bis(trinitromethyl)-3,3’-azo-1H-1,2,4-triazole (bottom) are more stable than other energy-rich materials.
Figure of explosive triazoles
Credit: J. Am. Chem. Soc.
New explosive triazole salts made from 5-nitro-3-trinitromethyl-1H-1,2,4-triazole (top) and 5,5’-bis(trinitromethyl)-3,3’-azo-1H-1,2,4-triazole (bottom) are more stable than other energy-rich materials.

When designing new explosive materials, chemists face a major hurdle: Many desirable characteristics come at the expense of others. For example, compounds that pack a large amount of energy into their bonds—and therefore produce a bigger bang—are also more likely to detonate unintentionally. Researchers may have found a happy medium with a new family of energetic triazole salts (J. Am. Chem. Soc., DOI: 10.1021/ja208990z).

The new nitro-substituted triazole salts have explosive properties similar to those of traditional explosives, but they are less impact-sensitive, a measure of an explosive’s stability, says Jean’ne Shreeve, from the University of Idaho, Moscow.

Her team looked to triazoles, because they fall between tetrazoles, which have high energy density but low stability, and imidazoles, which are more stable but less energetic.

The chemists generated a library of ten salts by reacting two acidic triazole molecules they had previously designed (J. Am. Chem. Soc., DOI: 10.1021/ja2013455) with several basic compounds. They then measured each salt’s density and calculated its heat of formation, two properties that together describe the amount of energy contained in an explosive material. The scientists also determined each salt’s impact sensitivity by dropping a weight onto about 40 mg of the compound to find the lowest force necessary to cause a flame or explosion.

The researchers found that several of the high-energy salts were less impact-sensitive than traditional explosives. For example, one of the salts formed from 5,5’-bis(trinitromethyl)-3,3’-azo-1H-1,2,4-triazole has comparable energy density to research department explosive (RDX), a commonly used explosive, but requires about twice as much force to detonate as RDX does.

Shreeve hopes that other researcher will investigate the compounds’ potential for real-life applications.

Advertisement

Article:

This article has been sent to the following recipient:

0 /1 FREE ARTICLES LEFT THIS MONTH Remaining
Chemistry matters. Join us to get the news you need.