New mesomorphic side-on materials containing high birefringent groups (tolanes and naphthalenes) have been designed and synthesized. We present the synthesis and characterization of 6-(4-acryloyloxybutanyloxy)-1,4{bis-[2-(6-propanoxynaphthyl)]diethyn}benzoate and 6-(4-acryloyloxybutanyloxy)-1,4{bis-[2-(6-butanoxy)naphthyl)]}diethyn}benzoateand their corresponding polymers. The first monomer exhibits both enantiotropic smectic C and nematic mesophases, while the second monomer exhibits only a monotropic cholesteric mesophase. The effect of the second monomer on the birefringence of reflective cholesteric displays is reported.