Well-defined polystyrene (PSt), poly(epsilon-caprolactone) (PCL) or poly(2-methyloxazoline) (POx) based polymers containing mid- or end-chain 2,5- or 3,5-dibromobenzene moieties were prepared by controlled polymerization methods, such as atom transfer radical polymerization (ATRP), ring opening polymerization (ROP), or cationic ring opening polymerization (CROP). These polymers were subsequently modified by Suzuki type coupling reactions with 2-thiophene boronic acid. The resulting polymers, containing a conjugated sequence with 2-thienyl groups at the extremities, could be further used as macromonomers in chemical oxidative polymerization in the presence of anhydrous FeCl3. Poly(thienyl-phenylene)s having the respective PSt or PCL chains as lateral subtituents were obtained in this way. All the starting, intermediate, or final polymers were structurally analyzed by spectroscopic methods (H-1 and C-13 NMR, IR) and gel permeation chromatography (GPC) measurements. Thermal behavior of the macromonomers and final polymers was investigated by differential scanning calorimetry (DSC) analyses. Optical properties of the polymers were monitored by UV and fluorescence spectroscopy. The emission spectra of the polymers show a clear bathochromic shift of the lambda(max) emission in all the cases with respect to the monomers because of the extending of the conjugation length. (c) 2007 Wiley Periodicals, Inc.