Infrared spectroscopy and Density Functional Theory of crystalline β-2,4,6,8,10,12-hexanitrohexaaziosowurtzitane (β CL-20) in the region of its C–H stretching vibrations

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 114; pp. 708 - 712
• Main Authors: Behler, K.D., Pesce-Rodriguez, R., Cabalo, J., Sausa, R.
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 01.10.2013
• Subjects: Bridged-Ring Compounds - chemistry; Crystallization; Models, Molecular; Quantum Theory; Spectroscopy, Fourier Transform Infrared; Spectrum Analysis, Raman
• ISSN: 1386-1425; 1873-3557
• DOI: 10.1016/j.saa.2013.05.075

[Display omitted] •The CH stretching vibrations of energetic material β-CL-20 were investigated.•IR, Raman, Laser Photoacoustics, and Density Functional Theory (DFT) were employed.•The C–H bond energy of CL-20 was determined experimentally and by DFT. Molecular vibrational spectroscopy provides a useful tool for material characterization and model verification. We examine the CH stretching fundamental and overtones of energetic material β-2,4,6,8,10,12-hexanitrohexaaziosowurtzitane (β-CL-20) by Raman spectroscopy, Fourier Transform Infrared Spectroscopy, and Laser Photoacoustic Overtone Spectroscopy, and utilize Density Functional Theory to calculate the C–H bond energy of β-CL-20 in a crystal. The spectra reveal four intense and distinct features, whose analysis yields C–H stretching fundamental frequencies and anharmonicity values that range from 3137 to 3170cm−1 and 53.8 to 58.8cm−1, respectively. From these data, we estimate an average value of 42,700cm−1 (5.29eV) for the C–H bond energy, a value that agrees with our quantum mechanical calculations.