We report on a series of blue emitting compounds based on a biphenyl moiety coupled to two alkoxy-substituted styrene units. Their photo-electronic. and physico-chemical properties can be tailored by changing the position of the alkyloxy substituent on the peripheral phenyl rings. The sequence of absorption, and photoluminescence maxima in solution spectra can be rationalized by the position-dependent inductive electron accepting, and mesomeric donating effects, the alkoxy groups have on the HOMO, and LUMO energies. Host-guest blue-emission OLEDs have been fabricated using the bis(ortho,meta) compound (23OVBP). Doping with 2-(4-biphenyl)-5-(4-tertbutylphenyl)-1,3,4-oxadiazole (PBD) into the blend film significantly enhances the external quantum efficiency, and the brightness, and also lowers the operating voltage. OLED performance depends upon the PBD concentration. Optimal blue emission with a quantum efficiency of 0.7%. and brightness of 1600 Cd/m(2) at 100 mA/cm(2) was achieved in devices with 60% PBD. (C) 2003 Elsevier B.V. All rights reserved.