Nickel Perfluoroalkyl Complexes Supported by Simple Acetate Co-Ligands

The interaction of tetramethylammonium acetate with [(MeCN)2Ni(CF3)2], [(MeCN)2Ni(C2F5)2], and [NMe4][(MeCN)Ni(CF3)3] was explored by 19F NMR spectroscopy. We show that, depending on the nature of the nickel complex, one or two acetate ligands can add to the metal center and replace the nickel-bound acetonitriles, depending on the acetate concentration. The number of acetates that could bind to nickel, and whether the resulting complex exists as a monomer or dimer, was determined to be dependent on the nature of the fluoroalkyl ligand. Moreover, we observe that oxidation of the nickel center of [(MeCN)2Ni(CF3)2] in the presence of two equivalents of acetate leads cleanly to the octahedral, paramagnetic, and anionic nickel(III) complex [NMe4][(OAc)2Ni(CF3)2.