A new class of cationic organoiron polynorbornenes containing azo dyes

Ring-opening metathesis polymerization of novel organoiron norbornene monomers functionalized with azobenzene chromophores using the Grubbs catalyst resulted in the production of the corresponding cationic organoiron polynorbornenes. UV-vis analysis of the organometallic polymers in DMF showed maxima from 420-430 nm, and upon acidification a bathochromic shift to 510-520 nm was observed. Cyclic voltammetric studies showed that the iron centers underwent reversible reduction steps between -1.2 and -1.4 V. Thermogravimetric analysis of the organoiron polymers showed two weight loss steps from 225 to 255 degreesC and from 400 to 510 degreesC. Differential scanning calorimetry showed that the cationic organoiron polynorbornenes had glass transition temperatures (T-g) between 145 and 178 degreesC, while the T-g values of their organic analogs occurred between 99 and 104 degreesC.