| abstract |
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. |