| abstract |
The present invention relates to a compound with the general formula (I): LnAmMXk, in which L is a borata benzene ligand of the general formula (II), in which the radicals R are identical or different and are a hydrogen atom or a C1-C10-carbon-containing group, A corresponds to a .pi.-ligand such as cyclopentadienyl, M is a metal of group IVb of the periodic system of elements, and X are identical or different and are a hydrogen atom, a C1-C40-carbon-containing group, an OH group, a halogen atom or NR22, n is a whole number 1 or 2, m is a whole number 0 or 1 and k is a whole number from 1 to 3, the sum of n+m+k being 3 or 4. The present invention also relates to a process for the preparation of the transition metal compound and the use thereof as catalyst constituent when preparing polyolefins. |