Shock Wave Compression of Three Polynuclear Aromatic Compounds

Abstract

Polycrystalline samples of anthracene, phenanthrene, and pyrene have been stressed with shock waves to pressures of 550 kbar. States in the stressed samples were determined by measuring shock wave velocities in the samples and in an 1100 aluminum base plate used as a standard. An abrupt increase in the compressibility was noted for each material: it occurred at 176 kbar for anthracene, 201 kbar for phenanthrene, and 234 kbar for pyrene. This increase is believed to be associated with an intermolecular coupling reaction. Recovered samples of anthracene did exhibit this coupled structure. The Hugoniot and calculated isotherm both indicate that anthracene is more compressible than was previously thought. The equation of state of 1100 aluminum was determined during this work.

The equation of state and nonmetal–metal transition of benzene under shock compression

“…6 As pressure increases, benzene has been found to decompose at 13 GPa along its Hugoniot. [7][8][9][10][11] At high static and dynamic temperatures and pressures, benzene mainly converts into defective carbon nanoparticles and H 2 , with the possible products of small concentrations of polycyclic aromatic hydrocarbons, such as alkanes. 12,13 Such reactions have also been found to be similar to the detonation of explosive materials.…”

“…Researches on benzene properties under shock conditions start from the plate impact experiments [6]. As pressure increases, benzene has been found to decompose at 13 GPa along its Hugoniot [7,8,9,10,11]. At high static and dynamic temperatures and pressures, benzene mainly converts into defective carbon nanoparticles and H 2 , with the possible products of small concentrations of polycyclic aromatic hydrocarbons, such as alkanes [12,13].…”

A quantum chemistry study of Diels–Alder dimerizations in benzene and anthracene

“…5,7 However, the peak pertaining to dimeric anthracene extends over several tens of amu, demonstrating that subsequent reactions of the dimers could be occurring. Warnes 5 suggested that one such reaction might be dehydrogenation.…”

“…Similar to that of benzene, the Hugoniot of liquid benzene has a discontinuity in its slope ͑i.e., a cusp, at 17.6 GPa͒. 5 Warnes suggested, based on mass spectrometry data, that one chemical product of shocked anthracene could be bianthracenyl ͑C 28 H 18 ͒. In 1994, Engelke and Blais 7 confirmed the production of chemically bound dimer above pressures of 18.4 GPa, corresponding roughly to the cusp in the shock Hugoniot of anthracene.…”

“…The principal shock Hugoniots of several other aromatic molecular compounds, including toluene, anthracene, phenanthrene, and pyrene, have slope discontinuities, while those of the nonaromatic compounds, 1,4-cyclohexadiene, cyclohexene, and cyclohexane, do not. 3,5,6 Anthracene ͑C 14 H 10 ͒ has been used as a benchmark system for understanding the effects of shock compression on molecular crystals. Similar to that of benzene, the Hugoniot of liquid benzene has a discontinuity in its slope ͑i.e., a cusp, at 17.6 GPa͒.…”