Dynamical characterization of rotationally hindered species in liquids

Abstract

[EN]The rotational dynamics of HCl in liquid Ar has been studied by means of molecular-dynamicssimulations. We calculate the lifetimes of weakly bound HCl Ar dimers induced by the anisotropic pair interaction. It is shown that, although lifetimes are small with respect to the reorientational decorrelation, the time interval between the breaking down and formation of the next dimer is negligibly small. Thus, with respect to the rotational dynamics of the probe, the effect is similar tothat and eventually would cause a time-stable complex. This provokes a peculiar hindered rotation of the diatomic in the liquid which is macroscopically embodied in the infrared spectrum of the solution as a Q-branch nonexistent otherwise.