Abstract: 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.

Abstract: 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.

Abstract: The invention relates to a process for preparing racemic metallocene complexes by reacting transition metal complexes with cyclopentadienyl derivatives of alkali metals or alkaline earth metals and heating the reaction mixture obtained in this way to a temperature in the range from ?78 to 250° C., to the corresponding metallocene complexes themselves and to their use as catalysts or as constituents of catalysts for the polymerization of olefinically unsaturated compounds or as reagents or catalysts in stereoselective synthesis.

Abstract: The invention relates to a process for preparing racemic metallocene biphenoxide complexes by reacting bridged transition metal complexes with cyclopentadienyl derivatives of alkali metals or alkaline earth metals and heating the reaction mixture obtained in this way to a temperature in the range from ?78 to 250° C., to the corresponding metallocene biphenoxide complexes and to their use as catalysts or as constituents of catalysts for the polymerization of olefinically unsaturated compounds or as reagents or catalysts in stereoselective synthesis.

Abstract: Novel metallocene monohalides can be used in the polymerization of olefins.

Abstract: The invention relates to a process for preparing racemic metallocene complexes by reacting transition metal complexes with cyclopentadienyl derivatives of alkali metals or alkaline earth metals and heating the reaction mixture obtained in this way to a temperature in the range from ?78 to 250° C., to the corresponding metallocene complexes themselves and to their use as catalysts or as constituents of catalysts for the polymerization of olefinically unsaturated compounds or as reagents or catalysts in stereoselective synthesis.

Abstract: The invention relates to a process for preparing racemic metallocene biphenoxide complexes by reacting bridged transition metal complexes with cyclopentadienyl derivatives of alkali metals or alkaline earth metals and heating the reaction mixture obtained in this way to a temperature in the range from ?78 to 250° C., to the corresponding metallocene biphenoxide complexes and to their use as catalysts or as constituents of catalysts for the polymerization of olefinically unsaturated compounds or as reagents or catalysts in stereoselective synthesis.

Abstract: A process for purifying metallocenes in which a sparingly soluble metallocene halide is converted into a readily soluble and readily crystallizable metallocene by replacement of at least one halide ligand by an alternative negatively charged ligand and the metallocene obtained in this way is subsequently purified by crystallization.

Abstract: The present invention relates to a process for preparing monoaryloxy-metallocenes of the formula (II), which comprises reacting a ligand starting compound of the formula (III) with a transition metal compound of the formula (I), where the symbols are as defined in the claims.

Abstract: Racemic metallocene complexes are prepared by reacting bridged or unbridged transition metal complexes with cyclopentadienyl derivatives of alkali metals or alkaline earth metals and, if desired, subsequently replacing the aromatic ligands.

Abstract: A process for preparing metallocene complexes of the general ##STR1## in which the substituents have the following meanings:M is titanium, zirconium, hafnium, vanadium, niobium or tantalum,X is fluorine, chlorine, bromine, iodine, hydrogen, C.sub.1 -C.sub.10 -alkyl, C.sub.6 -C.sub.15 -aryl or --OR.sup.5,where R.sup.5 is C.sub.1 -C.sub.10 -alkyl, C.sub.6 -C.sub.15 -aryl, alkylaryl, aryl-alkyl, fluoroalkyl or fluoroaryl with, in each case, 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical,R.sup.1 to R.sup.4 and R.sup.6 to R.sup.9 are hydrogen, C.sub.1 -C.sub.10 -alkyl, 5- to 7-membered cycloalkyl which can in turn carry C.sub.1 -C.sub.10 -alkyls as substituents, or C.sub.6 -C.sub.15 -aryl or aryl-alkyl, it also being possible where appropriate for two adjacent radicals together to be cyclic groups having 4 to 15 carbon atoms, or Si(R.sup.10).sub.3 withR.sup.10 being C.sub.1 -C.sub.10 -alkyl, C.sub.6 -C.sub.15 -aryl or C.sub.3 -C.sub.