Pyrene was electrochemically polymerized in the mixed electrolytes of boron trifluoride diethyl etherate (FIFEE) containing a certain amount of trifluoroacetic acid (TFA) and polyethylene glycol (PEG) with molar mass of 400 g (PEG 400). The oxidation potential of pyrene in these media was measured to be approximately 0.65 V (vs. SCE), which was much lower than that detected in a neutral electrolyte such as acetonitrile (1.15 V vs. SCE). The structure of the product was studied by matrix assisted laser desorption ionization/time-of-flight (MALDI/TOF) mass spectroscopy, UV-Vis, infrared and Raman spectroscopies. The results indicated that the product was composed of oligomers formed by alpha,alpha-coupling of the pyrene rings, and could be called as oligopyrene. The as-grown oligopyrene films showed microstructures with morphology like spheres, nanosheet networks and cups. The oligopyrene is electrochemically active and can emit strong blue light, which provide potential applications in fabrication of organic electronic displays and electrolurninescent devices. (c) 2005 Elsevier B.V. All rights reserved.