Conversion of imine ligands in allyl–nickel(II) complexes

Interaction of Ni(allyl)2 and bidentate nitrogen-containing ligands (phenanthroline-1,10; bis(2,6-diisopropylphenyl)diazabutadiene) has been studied. It has been shown that coordination of diimine ligands proceeds with transfer of an allylnickel group to the diimine frame and formation of a covalent Ni–N bond giving rise to imine(amide)Ni(II) complexes. In the case of phenanthroline dearomatization of one heteroaromatic ring takes place. The low-spin imine(amide)allyl complexes (allyl)Ni(C15H15N2) (1) and (allyl)Ni(C29H42N2) (3) have been isolated as crystals and characterized by solution spectroscopy. Combining two molar equivalents of phenanthroline-1,10 with Ni(allyl)2 results in the transfer of both allyl groups and formation of the high-spin imine(amide)Ni(II) complex Ni(C15H15N2)2 (2).

Graphical abstractThe reaction of bis(π-allyl)nickel with phenanthroline results in dearomatization of one heteroaromatic ring and formation of an imine(amide)nickel complex.Figure optionsDownload full-size imageDownload as PowerPoint slide