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Abstract:For the alternating copolymerization of CO 2 and cyclohexene oxide, a variety of zinc acetate complexes with new aminoimidoacrylate ligands has been synthesized and tested as catalysts. All complexes catalyzed the reaction and structure-activity investigations revealed that the highest activities and selectivities were reached when the ligand's aromatic rings were 2,6-substituted by alkyl groups of different size (isopropyl versus methyl) and when the ligand backbone embodied an electron-withdrawing cyano group. Furthermore, these complexes catalyzed the terpolymerization of CO 2 , cyclohexene oxide and lactide to give poly(cyclohexyl carbonateco-lactide) and the composition of the polymer was adjustable by the monomer feed.

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Nickel(II)−aminoacrylate, −aminoiminoacrylate, and −amidoiminomalonate complexes 1−4 are suitable precursors together with appropriate cocatalysts for the catalytic dimerization of ethylene, propylene, and α-olefins with short chain lengths such as 1-hexene. Suitable ligands IV−VI, VIII, X, and XII generate nickel(II) compounds 1−4 active for these catalytic dimerizations. The influence of different substituents attached to the coordinating ligand backbone is tested in the catalytic reactions. Several novel monodentate and chelate nickel(II) precursor complexes 1 and 3 were isolated and also characterized by X-ray structure analysis.