Abstract: The present invention relates to a new metallocene having the formula (I) ##STR1## where M is a metal of group IVb, Vb or VIb of the Periodic Table of the Elements, in particular Ti, Zr and Hf,X are identical or different and are each a hydrogen atom, a C.sub.1 -C.sub.40 -hydrocarbon group such as a C.sub.1 -C.sub.10 -alkyl, C.sub.1 -C.sub.10 -alkoxy, C.sub.6 -C.sub.10 -aryl, C.sub.6 -C.sub.10 -aryloxy, C.sub.2 -C.sub.10 -alkenyl, C.sub.7 -C.sub.40 -arylalkyl, C.sub.7 -C.sub.40 -alkylaryl or C.sub.8 -C.sub.40 -arylalkenyl group, an OH group, a halogen atom or a pseudohalogen such as nitrile,R.sup.1 to R.sup.5 are identical or different and, independently of one another, are each a hydrogen atom, a C.sub.1 -C.sub.30 -hydrocarbon radical such as C.sub.1 -C.sub.20 -alkyl or C.sub.6 -C.sub.20 -aryl, or a carbon-containing radical having from 1 to 10 carbon atoms and one or more heteroatoms selected from the group consisting of O, N, Si, Ge and P, where in each case two adjacent radicals R.sup.4 and/or R.sup.

Abstract: The present invention relates to a process for the hydrogenation of metallocenes, which comprises treating at least one metallocene containing at least one double bond and/or at least one aromatic substituent in at least one nonhalogenated solvent with hydrogen in the presence of at least one hydrogenation catalyst.