Structure and molecular dynamics of crystalline and liquid anthracene and naphthalene: Possible transient rotator phase of naphthalene

Patrice Bordat (1) , Ross Brown (1)

1 IPREM - Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux

We examine the structural and dynamical properties of the crystal and liquid states of anthracene and naphthalene, with special attention to melting. This molecular dynamics study is based on an all-atom force field, which we optimized for simulations of solid and liquid anthracene, over wide ranges of temperature and pressure. The force field is shown to be transferable to naphthalene. Local ordering of the simulated liquids is in fair agreement with structures deduced in the literature from X-ray scattering, while providing a much more detailed picture. In analogy with the rich polymorphism of substituted benzene and naphthalene complexes, we find for naphthalene (but not anthracene) a two-step melting process with a transient rotator phase in which rotational jumps precede the onset of full melting with translational diffusion. © 2009 American Institute of Physics.

Domaines: Chimie

Patrice Bordat, Ross Brown. Structure and molecular dynamics of crystalline and liquid anthracene and naphthalene: Possible transient rotator phase of naphthalene. Journal of Chemical Physics, 2009, 130 (12), ⟨10.1063/1.3093065⟩. ⟨hal-01567168⟩