Extended cooperative electronic effects in poly((E,E)‐[6.2]paracyclophane‐1,5‐diene)

Fluorescence spectroscopy of poly((E,E)‐[6.2]paracyclophane‐1,5‐diene) shows the existence of several emission maxima which appear at wavelengths longer than that of the [3.2]paracyclophane repeat‐unit excimer. These maxima appear to be emission bands due to “extended excimer” fluorescence from multiples of electronically interacting repeat units. Oxidation of the polymer by exposure to iodine vapor results in a material which exhibits a strong, asymmetric electron‐spin‐resonance spectrum with g = ca. 2.00 and a DC conductivity of 5 X 10—4 S‐cm—1. These results are interpreted by a model in which segments of interacting radical cation salts occur pendant to and along the polymer chains but are of random length and orientation in the bulk polymer. Similar results were obtained for a structurally related polymer containing [3.3]paracyclophane rings.