Process for the preparation of bridged cyclopentadienylmagnesium compounds and use thereof for preparing metallocenes

A process for preparing a compound of the general formula (1)

• Q(CpR.sub.a)(Cp'R'.sub.a ')Mg (1)
• wherein
• Cp is a cyclopentadienyl or an indenyl radical;
• R and R' are the same or different and each is selected from the group consisting of alkyl, phosphine, amino, alkylamino, dialkylamino, alkoxy, alkoxy-alkyl, aryl-alkyl, and aryloxy-alkyl groups;
• 0.ltoreq.a.ltoreq.4 and 0.ltoreq.a'.ltoreq.4;
• Cp' is cyclopentadienyl or indenyl, or when a' is 1, Cp'R' can be NR" wherein R" is a C.sub.1 -C.sub.12 alkyl or a C.sub.6 -C.sub.10 aryl radical;
• and
• Q is a single-membered or multi-membered bridge between Cp and Cp' and represents
• (R.sup.1 --Z--R.sup.2).sub.b,
• wherein
• R.sup.1 and R.sup.2 are identical or different and each is a hydrogen atom, a C.sub.1 -C.sub.10 alkyl group or a C.sub.6 -C.sub.10 -aryl group;
• Z is carbon, silicon or germanium;
• and b is 1, 2 or 3;
• said process comprising reacting a bridged cyclopentadienyl compound of the general formula Q(CpR.sub.a)(Cp'R'.sub.a ') in an inert solvent with one or more magnesium compounds of the formula (R.sup.3 R.sup.4).sub.c Mg, wherein R.sup.3 and R.sup.4 are each bonded to the Mg and each is independently of one another H or a C.sub.1 -C.sub.12 -alkyl radical and c is 0 or 1, under conditions effective to form a solution of said compound of formula (1) in said inert solvent.