Polymers from coumarins .2. Design and synthesis of novel main- and side-chain coumarin-containing polymers

Two novel coumarin-containing monomers, 3,3'-bis(ethoxycarbonyl)-6,6'-bicoumarin (3) and 7-[(2-norbornenyl)methoxy]coumarin (7), were prepared and characterized. They give polymers with (M) over bar(w) up to 350000 and are soluble in common organic solvents. Polymers were prepared by high temperature transesterification reaction (poly-3) and metathesis polymerization (poly-7). Poly-10 was prepared by direct activated polyamidation of 6-aminocoumarin-3-carboxylic acid (10). All polymers are amorphous with glass transition T-g of 121 and 64 degrees C for poly-3 and poly-7, respectively. High optical quality films can be prepared by solution casting, and in the case of poly-3 fibers can be drawn from the melt. All polymers show strong photoemission in the region from violet (poly-7) to blue-green (poly-10) (410-510 nm). An electroluminescent device was fabricated from poly-3 with turn-on voltage of 4 V.