Structural study of the 1-3-5 trifluorobenzene dimer stability: from liquid to gas densities using supercritical conditions (original) (raw)

The local ordering in 1,3,5-trifluorobenzene has been investigated under isothermal and isobaric conditions from the liquid to the supercritical domain using neutron diffraction and molecular dynamics simulation. The short-range local ordering existing at ambient conditions involving dimers in which the molecules are in a parallel stacked configuration, is Ž. progressively weakened at the isobaric condition P s 16 MPa upon increasing the temperature up to 573 K. Under Ž. Ž. isothermal conditions 573 K and as the density goes down to about r s rrr s 0.43 reduced density , although the r c Ž orientational ordering reaches in the fluid a more random distribution, dimers are still present two thirds of the proportion. estimated at ambient conditions. q 2000 Published by Elsevier Science B.V.