A number of classes of polynorbornenes containing cationic iron moieties within their side chains were prepared via ring-opening metathesis polymerization with a ruthenium-based catalyst. The iron-containing polymers displayed excellent solubility in polar organic solvents. The weight-average molecular weights of these polymeric materials were estimated to be in the range of 18,000-48,000. Thermogravimetric analysis of these polymers showed two distinct weight losses. The first weight loss was in the range of 204-260 degrees C and was due to the loss of the metallic moieties, whereas the second weight loss was observed at 368-512 degrees C and was due to the degradation of the polymer backbone. Cyclic voltammetry studies of the iron-containing polymers showed that the 18 e(-) cationic iron centers underwent a reduction to give the neutral 19 e- complexes at half-wave potential (E-1/2) = -1.105 V Photolysis of the metallated polymers led to the isolation of the norbornene polymers in very good yields. Differential scanning calorimetry studies showed a sharp increase in the glass-transition temperatures up to 91 degrees C when rigid aromatic side chains were incorporated into the norbornene polymers. (c) 2006 Wiley Periodicals, Inc.