  Organic semi-conductors have unique electronic properties and are important
systems both at the fundamental level and also for their applications in
electronic devices. In this article we focus on the particular case of rubrene
which has one of the best electronic transport properties for application
purposes. We show that this system can be well simulated by simple
tight-binding systems representing one-dimensional (1D) chains that are weakly
coupled to their neighboring chains in the same plane. This makes in principle
this rubrene system somehow intermediate between 1D and isotropic 2D models. We
analyse in detail the dc-transport and terahertz conductivity in the 1D and in
the anisotropic 2D models. The transient localisation scenario allows us to
reproduce satisfactorily some basics results such as mobility anisotropy and
orders of magnitude as well as ac-conductivity in the terahertz range. This
model shows in particular that even a weak inter-chain coupling is able to
improve notably the propagation along the chains. This suggest also that a
strong inter-chain coupling is important to get organic semi-conductors with
the best possible transport properties for applicative purposes.
