Synthesis, structure and butadiene polymerization behavior of CoCl2(PRxPh3 − x)2 (R = methyl, ethyl, propyl, allyl, isopropyl, cyclohexyl; x = 1, 2). Influence of the phosphorous ligand on polymerization stereoselectivity

The synthesis and characterization of cobalt(II) phosphine complexes of general formula CoCl2(PRxPh3 − x)2 (R = alkyl/allyl group; x = 1, 2) are described. The X-ray crystal structures of some of them are reported. Treatment of these complexes with methylaluminoxane leads to highly active catalysts giving 1,2 polybutadienes having different tacticity depending on the phosphorous ligand.