Thermal equation of state of solid naphthalene to 13 GPa and 773 K: in situ X-ray diffraction study and first principles calculations.
In a wide range of P-T conditions, such fundamental characteristics as compressibility and thermoelastic properties remain unknown for most classes of organic compounds. Here we attempt to clarify this issue by the example of naphthalene as a model representative of polycyclic aromatic hydrocarbons (PAHs). The elastic behavior of solid naphthalene was studied by in situ synchrotron powder X-ray diffraction up to 13 GPa and 773 K and first principles computations to 20 GPa and 773 K. Fitting of the P-V experimental data to Vinet equation of state yielded T 0 = 8.4(3) GPa and T' = 7.2 (3) at V0 = 361 Å(3), whereas the thermal expansion coefficient was found to be extremely low at P > 3 GPa (about 10(-5) K(-1)), in agreement with theoretical estimation. Such a diminishing of thermal effects with the pressure increase clearly demonstrates a specific feature of the high-pressure behavior of molecular crystals like PAHs, associated with a low energy of intermolecular interactions.
Sobolev Institute of Geology and Mineralogy, SB RAS, Novosibirsk 630090, Russia.
Anna Y
AY
Likhacheva
Sobolev Institute of Geology and Mineralogy, SB RAS, Novosibirsk 630090, Russia.
Sergey V
SV
Rashchenko
Sobolev Institute of Geology and Mineralogy, SB RAS, Novosibirsk 630090, Russia.
Artem D
AD
Chanyshev
Department of Physics and Technical Science, Gumilyov Eurasian National University, Astana, Kazakhstan.
Talgat M
TM
Inerbaev
Sobolev Institute of Geology and Mineralogy, SB RAS, Novosibirsk 630090, Russia.
Konstantin D
KD
Litasov
Department of Chemistry, University of South Dakota, Vermillion, South Dakota 57069, USA.
Dmitry S
DS
Kilin