Cationic allyl nickel complexes containing N,O-donor labile ligands: Synthesis and molecular characterisation

Three 2-iminofuran ligands 2-(N-2,6-diisopropylphenylformimino)furan (L1), 2-(N-2,6-dimethylphenylformimino)furan (L2) and 2-(N-4-methoxyphenylformimino)furan (L3) were obtained by condensation reactions of the respective anilines with furfural. The eta(3)-allyl Ni(II) cationic complexes 1-3 have been synthesised by reacting [Ni(eta(3)-C3H5)(mu-Br)](2) with the corresponding ligands L1-L3, in the presence of TIPF6. All complexes have been characterised by FT-IR, NMR spectroscopy and elemental analysis. The molecular structure of complex 2 has been determined by single crystal X-Ray diffraction. Complexes 1 and 2 have displayed a mono bidentate chelation mode of the respective ligand, while complex 3 showed a bis monodentate coordination framework. The respective complexes were studied by DFT calculations, showing a tendency to form the bis monodentate species, the formation of complex 3 being clearly the most favoured one. (C) 2019 Elsevier B.V. All rights reserved.