Functionalized carbon monoxide copolymers

A process for preparing functionalized linear alternating carbon monoxide copolymers, which comprises copolymerizing carbon monoxide with at least one 1-alkene (A) which is an aryl derivative containing one or more polar groups and substituted with at least one terminal allyl and/or homoallyl unit, and, if desired, at least one C2-C10-1-alkene (B) in a virtually alcohol-free or water-free polymerization medium in the presence of a catalyst whose active material is formed from

• a) a metal complex of the formula (IIIa) or (IIIb)
• where
• M is a metal of group VIIIB of the Periodic Table of the Elements,
• E1, E2 are each an element from group VA of the Periodic Table of the Elements,
• Z is a bridging structural unit comprising one, two, three or four structural subunits of elements of group IVA, VA, VIA of the Periodic Table of the elements,
• Ra to Rd are substituents selected from the group consisting of aromatic radicals which radicals may contain one or more elements of groups IVA, VA VIA and VIIA of the Periodic Table of the Elements,
• Re to Rh are each, independently of one another, hydrogen, linear or branched C1-C6-alkyl or
• Rf and Rg are together a five- or six-membered carbocycle or heterocycle,
• L1, L2 are formally uncharged Lewis base ligands,
• T is a monovalent or divalent anion,
• r,s are each 1 or 2,
• provided r×s=2, and
• b) an activator component which contains a hydroxyl group in the molecule and is used in a an amount of from 0 to 1500 molar equivalents, based on M in (III).