Zinc complexes chelated by bifunctional ketiminate ligands: Structure, reactivity and possible applications in initiation of ROP and copolymerization of epoxides with carbon dioxide

• Homo- and heteroleptic zinc complexes were prepared.
• Monoanionic potentially terdenate ketiminate ligands were used.
• Reactivity studies of heteroleptic ethyl zinc complex with alcohols and amines was performed.
• Heteroleptic ethyl zinc complex was screened in as a catalyst in various co/polymerization reactions.

Bifunctional ketiminate zinc complexes were synthesized via alkyl or LiCl elimination route from appropriate zinc species (ZnCl2 or ZnEt2) and methoxyaryl substituted monoanionic ketimine {[2- or 3- or 4-(MeO)C6H4]}N(H)C(Me)=CHC(Me)=O. Homo- or heteroleptic complexes were prepared and characterized by the help of multinuclear NMR spectroscopy techniques. One of the heteroleptic ethyl substituted zinc complexes - {κ2-N,O-[(2-MeO)C6H4NC(Me)–CHC(Me)–O]ZnEt}2 was selected for further reactivity experiments with alcohols and amines. Molecular structures of some products were determined by X-Ray diffraction methods showing di- or trinuclear arrangement in solid state caused by the presence of intramolecular zinc–oxygen or zinc–nitrogen bridges. {κ2-N,O-[(2-MeO)C6H4NC(Me)–CHC(Me)–O]ZnEt}2 was also screened for of its catalytic activity in co/polymerization reactions (ROP: trimethylene carbonate, ɛ-caprolactone, l-lactide; copolymerization of epoxides with CO2).

Homo- and heteroleptic zinc complexes containing monoanionic methoxyaryl substituted ketiminate ligands were synthesized and characterized. Selected complex was studied for further reactivity with alcohols and amines and also screened as co-initiator of various co/polymerization reactions.Figure optionsDownload as PowerPoint slide