High-density HNIW/TNT cocrystal synthesized using a green chemical method

Area of Science:

• Materials Science
• Chemistry
• Crystallography

Background:

• Achieving higher density in energetic materials is crucial for improved performance.
• CL-20 (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane) and TNT (2,4,6-trinitrotoluene) are key energetic compounds.
• Cocrystallization offers a pathway to modify material properties.

Purpose of the Study:

• To synthesize and characterize novel cocrystals of CL-20 and TNT.
• To investigate the structural and energetic properties of the new cocrystal.
• To explore methods for enhancing the density and stability of energetic materials.

Main Methods:

• Green chemical synthesis using ethanol.
• Single-crystal and powder X-ray diffraction for structural analysis.
• Fourier transform-infrared spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy for characterization.
• Thermodynamic analysis of decomposition.

Main Results:

• A new CL-20/TNT cocrystal (C13H11N15O18) was successfully synthesized with a higher density (1.934 g cm⁻³) than previously reported.
• The cocrystal structure features three one-dimensional hydrogen-bonded chains, influencing its properties.
• The new cocrystal demonstrates increased thermodynamic stability and reduced mechanical sensitivity compared to CL-20.
• Detonation velocity remains comparable to CL-20, while sensitivity is lower.

Conclusions:

• Cocrystallization of CL-20 with TNT is an effective strategy to increase material density and enhance stability.
• The identified hydrogen bonding network plays a critical role in the cocrystal's improved characteristics.
• This high-density cocrystal represents a promising advancement in energetic materials research.