The reaction of a series of polycyclic aromatic hydrocarbons with the layered host FeOCl has been examined. Arenes with ionization potentials ≤ ca. 7 eV react with FeOCl via an intercalation process. The intercalation compounds FeOCl(perylene)1/9 and FeOCl (tetracene)1/12 have been characterized. Powder X-ray diffraction studies of microcrystalline powders and oriented films of these materials indicate that in each case the guest molecules are oriented with their molecular planes perpendicular to the layers of the host lattice. FTIR spectra indicate that intercalation of these molecules into FeOCl occurs via a redox mechanism, in which approximately one electron is transferred to the host lattice per guest molecule. Temperature dependent conductivity measurements show a 105-fold increase in conductivity over that of unintercalated FeOCl, with apparent bandgaps of 0.29 and 0.27 eV for the perylene and tetracene intercalates, respectively. © 1990, American Chemical Society. All rights reserved.