New cobalt dichloride complexes with pyridyl-phosphine bidentate ligands were synthesized and characterized. Single crystals were obtained, and their molecular structure was determined by single crystal X-ray diffraction method. The complexes were then used in combination with methylaluminoxane (MAO) for the polymerization of 1,3-butadiene, obtaining predominantly cis-1,4 polymers or with a mixed cis-1,4/1,2 structure depending on the type of ligand and on the MAO/Co molar ratio. A plausible interpretation for this behavior is provided.

中文翻译：

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具有吡啶基-膦双齿配体的二氯化钴配合物：1,3-丁二烯聚合中的合成、表征和行为

合成并表征了具有吡啶基-膦双齿配体的新型二氯化钴配合物。获得单晶，并通过单晶X射线衍射法确定其分子结构。然后将配合物与甲基铝氧烷 (MAO) 结合用于 1,3-丁二烯的聚合，主要获得顺式-1,4 聚合物或混合顺式-1,4/1,2 结构，具体取决于配体类型和 MAO/Co 摩尔比。提供了对此行为的合理解释。