| abstract |
An organometallic compound obtainable by contacting n a) a compound having the following formula (I): n n n wherein R a , R b , R c and R d equal to or different from each other are hydrocarbon groups n b) a Lewis acid of formula (II) n MtR 1 3 (II) n wherein Mt is a metal belonging to Group 13 of the Periodic Table of the Elements (IUPAC); R 1 , equal to or different from each other, are selected from the group consisting of halogen, halogenated C 6 -C 20 aryl and halogenated C 7 -C 20 alkylaryl groups; two R 1 groups can also form with the metal Mt one condensed ring. n These compounds are useful as cocatalysts for polymerizing olefins |