Energetic N,N'-ethylene-bridged bis(nitropyrazoles): diversified functionalities and properties
Ping Yin1, Jiaheng Zhang, Damon A Parrish
1Department of Chemistry, University of Idaho, Moscow, Idaho, 83844-2343 (USA), Fax: (+1) 208-885-9146.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|October 22, 2014
Summary
Researchers synthesized novel N,N'-ethylene-bridged bis(nitropyrazoles) with diverse functional groups. The hexanitro derivative shows promising energetic properties and performance comparable to established energetic materials.
Area of Science:
- Organic Chemistry
- Materials Science
- Energetic Materials
Background:
- Development of new energetic materials is crucial for advancements in various fields.
- Nitropyrazole derivatives have shown potential as energetic compounds.
- Bridging pyrazole units can modify energetic properties and stability.
Purpose of the Study:
- To synthesize and characterize a new class of N,N'-ethylene-bridged bis(nitropyrazoles).
- To explore the influence of functional group transformations on energetic properties.
- To evaluate the detonation performance and sensitivity of the synthesized compounds.
Main Methods:
- Synthesis of N,N'-ethylene-bridged bis(nitropyrazoles) using dibromoethane and pyrazolate salts.
- Functional group transformations to create diverse derivatives (diamino, dichloro, dinitramino, diazido, hexanitro).
- Characterization using single-crystal X-ray diffraction, computational calculations (Gaussian 03, EXPLO5 v6.01) for heats of formation and detonation performance.
Main Results:
- Successful synthesis of a new class of N,N'-ethylene-bridged bis(nitropyrazoles).
- Structural elucidation of hexanitro and diazido derivatives via X-ray diffraction.
- The hexanitro derivative exhibits excellent energetic properties (density 1.84 g/cm³, decomposition temperature 250°C, detonation pressure 34.1 GPa, detonation velocity 8759 m/s) and competitive performance with 1,3,5-trinitrotriazacyclohexane.
Conclusions:
- N,N'-ethylene-bridged bis(nitropyrazoles) represent a promising class of energetic materials.
- The hexanitro derivative demonstrates superior energetic performance and stability.
- These compounds offer tunable sensitivity, ranging from insensitive to sensitive, based on functionalization.
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