BigPatents India

The invention relates to a process for preparing hydrogenated or partially hydrogenated, racemic ansa-metallocene complexes by reacting bridged or unbridged transition metal complexes with alkali metal compounds or alkaline earth metal compounds, heating the resulting reaction mixture to a temperature in the range from -78 to 250°C and at least partially hydrogenating the reaction products in the presence of a suitable catalyst, to the corresponding hydrogenated or partially hydrogenated metallocenes and to their use as catalysts or as a constituent of catalysts for the polymerization of olefinically unsaturated compounds or as reagents or catalysts in stereoselective synthesis.