  Brownian diffusion of rod-like polymers in the presence of randomly
distributed spherical obstacles is studied using molecular dynamics (MD)
simulations. It is observed that dependence of the reduced diffusion
coefficient of these macromolecules on the available volume fraction can be
described reasonably by a power law function. Despite the case of obstructed
diffusion of flexible polymers in which reduced diffusion coefficient has a
weak dependence on the polymer length, this dependence is noticeably strong in
the case of rod-like polymers. Diffusion of these macromolecules in the
presence of obstacles is observed that is anomalous at short time scales and
normal at long times. Duration time of the anomalous diffusion regime is found
that increases very rapidly with increasing both the polymer length and the
obstructed volume fraction. Dynamics of diffusion of these polymers is observed
that crosses over from Rouse to reptation type with increasing the density of
obstacles.
