Abstract: In a process for the racemoselective preparation of silicon-bridged dialkyl-ansa-metallocenes of the formula (I) comprises reaching a ligand starting compound of the formula (II) with a transition metal dialkyl compound of the formula (III) M1XxR12*Dy (III), where M1 is an element of group 4, 5 or 6 of the periodic Table of the Elements, R1 are identical C1-C20-alkyl or C7-C40-arylalkyl radicals, X are identical or different halogens, R2 are identical or different C1-C40 radicals, R3 are identical or different C1-C40 radicals, T is a divalent C1-C40 group which together with the cyclopentadienyl ring forms a further saturated or unsaturated ring system which has a ring size of from 5 to 12 atoms, where T may contain the heteroatoms Si, Ge, N, P, O or S in the ring system fused onto the cyclopentadienyl ring, M2 is Li, Na, K, MgCl, MgBr, MgI, Mg or Ca, D is an uncharged Lewis base ligand, x is equal to the oxidation number of M1 minus 2, y is from 0 to 2 and p is 1 in the case of doubly positively charged meta

Abstract: Ligand systems containing indenyl structures, transition metal compounds of the metallocene type and catalyst systems comprising such transition metal compounds are described. The novel transition metal compounds can be used in the polymerization of olefins, in particular to give polyolefins having a low molar mass.