Highly Stereospecific Polymerizations of 1,3-Butadiene with Cobalt(II) Pyridyl Bis(imine) Complexes
نویسندگان
چکیده
A series of prototypical Co(II)-based pyridyl bis(imine) complexes {[2(ArN=C(Me))2C5H3N]CoCl2} (Ar = 2,6-C6H3Me2, 2,5-C6H3Me2, 2,4-C6H3Me2, 2,3C6H3Me2) bearing two methyl substituents on each imine aryl group are studied as precatalysts for the homopolymerization of 1,3-butadiene. They showed very high polymerization activities associated with ethylaluminum sesquichloride (EAS) as a cocatalyst. The Co(II) catalysts containing less hindered pyridyl bis(imine) ligands, say [2-(2,3-C6H3Me2N=C(Me))2C5H3N]CoCl2 complex, showed highest activity to give high molecular weight polymers. All catalysts yielded cis-1,4-polybutadienes up to 96.4% with cis-1,4 regular structure.
منابع مشابه
Recent advances in the polymerization of butadiene over the last decade
The stereospecific polymerization of conjugated dienes began in 1954 with the first catalysts obtained by combining TiCl4 or TiCl3 with aluminum-alkyls, i.e. the catalytic systems previously employed for ethylene and propylene polymerizations. Subsequently, many other catalytic systems were obtained and examined by a combination of transition metal or lanthanide compounds with appropriate alkyl...
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