Synthesis and butadiene polymerization behaviors of cationic cobalt-based catalyst

A series of cationic cobalt-based compounds bearing different neutral N-bearing ligands (1,10-phenanthroline, bipyridine, benzimidazole, terpyridine) and anionic ligands (trifluoromethanesulfonate, methanesulfonate) were synthesized and the simple compound, Co(Phen)2Cl2, was also prepared as a reference compound. All the compounds were characterized along with infrared spectra analysis and some of them were further confirmed by single crystal X-ray crystallographic analysis. Upon activation with ethylaluminum sesquichloride, these cationic cobalt(II) compounds showed high catalytic activities for butadiene polymerization. The detailed investigations were carried out to disclose the influence of various polymerization conditions, sterical and electronic parameters of the ligands on their performing activities of the compounds.