Metal-Containing Polymers Synthesized via Acyclic Diene Metathesis (ADMET) Polymerization Using Electrochemically Reduced Tungsten-Based Catalyst: Polycarbogermanes

摘要

Various germanium-containing dienes, bis(4-pentenyl)diethylgermanium (1), bis(4-pente-nyl)dimethylgermanium (2) and bis(3-butenyl)diethylgermanium (3), were synthesized and polymerized using an electrochemically reduced tungsten-based catalyst system via acyclic diene metathesis (ADMET) polymerization. All polymer structures were characterized by ~1H-and ~(13)C-NMR spectroscopy. These results indicate the retention of the double bonds in the polymer structure with high trans content (57-70%) as expected from a step condensation reaction. These polymers have low molecular weight (M_W) that range from 7400 to 19,100. The thermal stability of polymers was evaluated by thermogravimetric analysis. The glass transition temperatures of the polymer of monomer 1, 2 and 3 were —24, -9 and -47℃, respectively. Synthesis, characterization and the general limitations of ADMET polymers obtained by this catalyst are discussed.