Many new solvents were investigated for the copolymerization of CO with ethylene to prepare polyketones with small reactor experiments.The backbone and the end groups of the polyketones prepared in different solvents were analyzed with high resolution 1H NMR and 13C NMR techniques.The experimental results showed that

besides in methanol

in acetone

propionaldehyde

N

N dimethylformamide

N

N dimethylacetamide

glacial acetic acid

dimethylsulfoxide

palladium(Ⅱ)-bisphosphine catalyst also had high reactivity

especially in glacial acetic acid

the copolymerization could be performed without anions of strong acid.The experimental results also showed that suitable solvent should have suitable stability on central metal palladium(II) besides acting as diluent.End groups analysis showed that the copolymerization was initiated by insertion of ethylene into Pd-H bond in non-alcohol solvents

was mainly initiated bu insertion of CO into Pd-OR bond in alcohol solvents.