Catalytic system and system for copolymerizing carbon monoxide with one or more olefins

Homogeneous catalytic system active in the preparation of alternating copolymers of olefins with carbon monoxide (CO), constituted by:

• (a) at least one salt of a metal of Group IB of the Periodic Table,
• (b) a bidentate chelating base containing two phosphorus or nitrogen atoms wherein the bidentate chelating base falls within the group of compounds having the general formula
• R.sub.1 R.sub.2 --M--R--M--R.sub.3 R.sub.4
• in which:
• M represents a phosphorus or nitrogen atom,
• R stands for a polymethylene radical containing from 2 to 3 carbon atoms, a cycloalkylidene radical containing from 2 to 10 carbon atoms, a phenylene radical,
• R.sub.1, R.sub.2, R.sub.3, and R.sub.4, which are the same or may be different from each other, represent an alkyl radical of from 1 to 6 carbon atoms, a cycloalkyl radical of from 3 to 6 carbon atoms, an aromatic radical of from 6 to 12 carbon atoms, and
• (c) an inorganic or organic oxidizing agent, wherein the inorganic oxidizing agent is nitrosonium tetrafluoroborate NOBF.sub.4, and the organic oxidizing agent is para-benzoquinone.