We have prepared and characterized several trithienylbenzenes. These compounds are used as reticulation points in poly(3-n-octylthiophene). It was necessary to study the reactivity of the reticulation points with regard to 3-n-octylthiophene. That is the reason why we have prepared copolymers starting from very high percentages of deuterated reticulation points (> 10%) and monitored their reactivities following the evolution of the C-D band in the infra-red spectra of the copolymers. The copolymers thus obtained contain from 10% to 30% of reticulation points. They swell in apolar solvents whereas the poly(reticulation point) (100% of reticulation points) does not swell. A low molar doping level (FeCl 3 6H 2 O, < 9%) leads to a non-negligible conductivity (0.1 to 0.2 S cm - 1 ) of these copolymers. In the same conditions, the poly(reticulation point) cannot be doped and thus remains insulating.