Standard microlithographic techniques can be used for the spatially controlled light-directed synthesis of poly(p-phenylene vinylene) (PPV) block copolymers. Microscalar linear and circular patterns can be prepared in the 25 mu m range. The success of the overall procedure rests on the photogeneration of triflic acid from triphenylsulfonium trifluoromethanesulfonate in a poly(9-hydroxy-[2.2]paracyclophan-1-ene) matrix to catalyze the formation of PPV. Absorption and photoluminescence studies were performed to demonstrate the efficiency of the conversion of the precursor polymer to PPV throughout the photolithographic sequence. FT-IR and UV-Vis data are also presented that illustrate how the precursor poly(paracyclophenes) can be patterned for certain block copolymer ratios in the absence of a photoacid generator. (C) 1998 Elsevier Science S.A. All rights reserved.