| abstract |
Metallocenes of the formula <IMAGE> wherein M is a metal from the group Ti, Zr, Hf, V, Nb, Ta or an element from the group of the lanthanides, X1 and X2 is an alkyl, alkoxy, aryl, aryloxy, alkenyl -, arylalkyl, alkylaryl or arylalkenyl group, hydrogen or halogen and L1 and L2 mean a hydrocarbon which can form a sandwich structure with M, at least L1 or L2 being substituted or condensed by a ferrocene or ruthenocene radical. R1 stands for C, Si, Ge or Sn or the entire bridge member A (R1) nB for an unsubstituted or substituted with A and / or B biphenylene radical, A and B have the meaning of X1 and X2, n is a whole Number from 0 to 4. |