A series of new segmented copolymers containing rn-phenylene in the chromophore unit have been synthesized by Wittig condensation. They are readily soluble in organic solvents and have high photoluminescence quantum yields in chloroform. Face-to-face pi -stacking in the solid state is limited or prevented by molecular nonlinearity due to the meta-linkage and by the presence of a bulky tert-butyl group in the chromophores. Single-layer electroluminescence devices with an ITO/polymer/Ca-Al configuration emitted in the blue region (470-490 nrn) for all of these systems.