| abstract |
ABSTRACT OF THE DISCLOSURE Alkoxides of transition metals, selected from the group consisting of tetravalent Ti, tetravalent and pentavalent V, tetravalent Cr and tetravalent Zr, are reduced to corre-sponding alkoxides of lower valency by reacting such higher valency metal alkoxides, in liquid phase, with vapors of at least one metal selected from the group consisting of alkaline earth, group III and group IV metals, and manganese. Very efficient polymerization catalysts for the polymeriza-tion of unsaturated compounds are thus obtained. |