Synthesis and Characterization of Ferrocene-Chelating Heteroscorpionate Complexes of Nickel(II) and Zinc(II)

The first example of a ferrocene-chelating heteroscorpionate, [Li­(THF)2]­[fc­(PPh2)­(BH­[(3,5-Me)2pz]2)] ((fcP,B)­Li­(THF)2, fc = 1,1′-ferrocenediyl) is described. Starting from a previously reported compound, fcBr­(PPh2), a series of ferrocene derivatives, fc­(PPh2)­(B­[OMe]2), [Li­(OEt2)]­[fc­(PPh2)­(BH3)], [Li­(THF)2]­[fc­(PPh2)­(BH­[(3,5-Me)2pz]2)] (pz = pyrazole), was isolated and characterized. Compound (fcP,B)­Li­(THF)2 allowed the synthesis of the corresponding nickel and zinc complexes, (fcP,B)­NiCl, (fcP,B)­NiMe, (fcP,B)­ZnCl, and (fcP,B)­ZnMe. All compounds were characterized by NMR spectroscopy, while the zinc and nickel complexes were also characterized by X-ray crystallography. The redox behavior of (fcP,B)­NiCl, (fcP,B)­NiMe, (fcP,B)­ZnCl, and (fcP,B)­ZnMe was studied by cyclic voltammetry and supported by density functional theory calculations.