876336-74-2Relevant academic research and scientific papers
Studies on nickel(II) complexes with amide-based ligands: Syntheses, structures, electrochemistry and oxidation chemistry
Singh, Jyoti,Hundal, Geeta,Gupta, Rajeev
experimental part, p. 2052 - 2063 (2009/03/11)
The present work discusses the nickel chemistry in a set of amide-based open-chain ligands with subtle differences in the backbone or terminal amine substituents. The ligands coordinate to the Ni2+ ion through the Namide and Namine atoms maintaining a square-planar geometry. Absorption spectra and NMR studies reveal that the solid-state square-planar geometry is retained in solution. The electrochemical results suggest that the NiIII/NiII redox couple primarily depends on the N4 donors, which is composed of two Namide and two Namine atoms and not on the peripheral substituents. All four ligands with variable backbone and substituents are equally competent in stabilizing the NiIII state. On the basis of electrochemical findings, chemical oxidations were carried out, and they reveal generation of the NiIII state in two cases, whereas decomposition was observed in others. Preliminary alkene epoxidation reactions suggest that the present nickel complexes transiently stabilize the higher oxidation state of the nickel ion that possibly participates in the oxidation of the substrates. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
