Olefin polymerisation catalyst

摘要

The invention concerns a catalyst for olefin polymerisation, of formula (I) wherein: E is an oxygen or sulphur atom; X is a phosphorus, arsenic or antimony atom; M is a nickel, palladium or platinum atom comprising a non-attributed valency; a is 1 or 2; R₁, R₂, R₃, identical or different can be selected among hydrogen, alkyl, cycloalkyl, aryl, alkylaryl, arylalkyl radicals, the hydroxyl radical, the alkoxide radicals (with 1 to 20 carbon atoms), the groups -C(O)OR'-, -SO₃Y; and Z represents a hydrocarbon radical comprising 2 to 3 carbon atoms; R represents a hydrocarbon radical of valency a, provided that at least one of the radicals Z or R bears at least an electroattractive substituent