Pressure dependence of the Raman and infrared spectra of. cap alpha. -,. beta. -,. gamma. -, and-, delta-octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine

Journal Article · Thu Aug 24 00:00:00 EDT 1978 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100506a011· OSTI ID:6822068

Goetz, F ^[1]; Brill, T B; Ferraro, J R

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1. Univ. of Delaware, Newark

The Raman and infrared spectra reported of the ..cap alpha..-, ..beta..-, ..gamma..-, and delta-polymorphs of HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) under pressure using a diamond anvil cell (DAC). The stability to pressure or the pressure-induced phase transitions were determined for each polymorph. Sample pressures up to 10 kbar were used in the Raman experiments; infrared spectra were recorded at pressures up to 54 kbar. The observed behavior of the polymorphic forms is as follows: ..beta..-HMX is stable up to 54 kbar and ..cap alpha..-HMX is stable up to 42 kbar. ..gamma..-HMX converts to ..beta..-HMX at 5.5 kbar, and delta-HMX converts to a mixture of ..cap alpha..- and ..beta..-HMX at pressures below 0.5 kbar. No new polymorphs were produced under pressure. An inverse relationship exists between temperature and pressure effects; the polymorph most stable at low temperature and having the smallest volume (..beta..-HMX) is the most stable at high pressure. The infrared spectra (600 to 1700 cm/sup -1/) of the solid HMX polymorphs at ambient pressure are reported for the first time without matrix effects. The -CH/sub 2/- and -NO/sub 2/ vibrational regions (>1200 cm/sup -1/) in the absence of the KBr matrix, and with the increased resolution obtained in the DAC, show minor differences from the KBr spectra reported in the literature. 2 tables, 6 figures.

• OSTI ID: 6822068
• Journal Information: J. Phys. Chem.; (United States), Vol. 82:17
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
HETEROCYCLIC COMPOUNDS
PHASE TRANSFORMATIONS
INFRARED SPECTRA
ISOMERS
PHASE STABILITY
PRESSURE DEPENDENCE
RAMAN EFFECT
TEMPERATURE DEPENDENCE
VERY HIGH PRESSURE
ORGANIC COMPOUNDS
SPECTRA
STABILITY
400301* - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)