Synthesis, characterization and catalytic studies of two Ni(II) complexes of pentane-2,4-dionate

• Published in: Inorganica Chimica Acta Vol. 471; pp. 777 - 781
• Main Authors: Affan, Mohammad A., Schatte, Gabriele, Jessop, Philip G.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 24-02-2018; Elsevier Science Ltd
• Subjects: Atomic structure; Carbon dioxide; Catalysis; Chemical synthesis; CO2 conversion; Coordination compounds; Crystal structure; Cubane; dmpe ligand; Fourier transforms; Infrared spectroscopy; Ligands; Ni(acac)2 complexes; Nickel; Oxygen atoms; Single crystals; X-ray diffraction; X-ray structures; Ni(acac)2 complexes; dmpe ligand; CO2 conversion; X-ray structures
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2017.11.057

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•Attempts to prepare Ni(acac) complexes of dmpe gave two unexpected products instead.•[Ni(acac)2(dmpeO2)]n, containing oxidized phosphines, is polymeric in the solid state.•[(Ni(acac)(MeO)(MeOH)]4 has a tetranuclear cubane structure.
Two nickel(II) complexes, [Ni(acac)2(dmpeO2)]n·2CHCl3 (1) and [(Ni(acac)(MeO)(MeOH)]4 (2) (acac− = pentane-2,4-dionato) have been synthesized and characterized by elemental analysis, FT-IR spectroscopy, and single crystal X-ray diffraction. The geometries around the central nickel(II) ion are distorted octahedral in both complexes. The equatorial plane includes four oxygen donor atoms of two acetylacetonato ligands and the axial positions are occupied by two oxygen atoms of two dmpeO2 ligands. Complex 1 has a polymeric chain structure in the solid state, while complex 2 has a tetranuclear cubane structure. These complexes are the first reported examples of polymeric and tetranuclear structures of Ni((II) containing acac- ligand. Neither complex is catalytically active for the hydrogenation of CO2 to formamide, even though a mixture of Ni(acac)2 and dmpe form a very active in situ catalyst together.