Two new poly(fluorenediylvinylene)s (CV and CF) with coumarin side chains were synthesized via Heck coupling. The coumarin segments were attached to the C-9 of fluorene through alkyl spacers. The polymers were soluble in common organic solvents such as tetrahydrofuran (THF), chloroform, dichloromethane, and toluene. The photoluminescence (PL), electroluminescence (EL), and electrochemical behavior of these polymers were studied. CV and CF thin films exhibited broad-band, bluish-green and orange PL emissions, with maxima at 475 and 585 nm, respectively. These PL maxima were redshifted in comparison with those measured in THF solutions. Aggregate formation played an important role in the solid state. The aggregation was more pronounced in CF thin films than CV thin films. Both polymers oxidized and reduced irreversibly. Light-emitting devices (LEDs) with indium tin oxide hole-injecting and aluminum electron-injecting electrodes were prepared and studied. The LEDs made of CV emitted green light, and the LEDs made of CF exhibited an orange EL emissions. (c) 2006 Wiley Periodicals, Inc.