HETEROLEPTIC ALKALINE-EARTH METAL COMPOUNDS AND METHODS FOR CARRYING OUT STEREOSELECTIVE ANIONIC POLYMERIZATION

摘要

Polymerization initiator comprising an alkaline earth metal compound chosen from the groupa) of heteroleptic alkaline earth metal compounds of the formula I orb) of cationic alkaline earth metal complexes of the formula II whereM: is Ca, Sr or Ba,L: is a polymerization-inactive ligand,R: is a polymerization-active ligand,D: is a donor ligand, andX: is a non-coordinating anion,and processes for the preparation of the polymerization initiators and processes for anionic polymerization in the presence of the polymerization initiators.