Cationic polymerization of dibenzofulvene is conducted using BF3-OEt2, CH3SO3H, CF3CO2H, and CH3CO2H as catalyst or initiator in CH2Cl2 under various conditions. The cationic polymerization leads to controlled stereochemistry and results in a pi-stacked polymer through the polymerization. The polymers synthesized using BF3-OEt2 and CH3SO3H appear to possess different pi-stacked structures. The polymer made using CH3SO3H has an all-trans main-chain C-C bond conformation while the one prepared using BF3-OEt2 may at least partially have a trans-gauche main-chain C-C bond conformation. pi-Stacked conformations are confirmed on the basis of remarkable anisotropy effects on aromatic signals in H-1 NMR spectra, hypochromic effects in electronic absorbance spectra, and dimer (excimer) emission in fluorescence spectra. pi-Stacked conformation is found even for oligomer samples with M-n of as low as about 700, indicating that the conformation created by the cationic polymerization is rather stable. (C) 2018 Elsevier Ltd. All rights reserved.