Synthesis and Characterization of Ferrocene-Chelating Heteroscorpionate Complexes of Nickel(11) and Zinc(II)

The first example of a ferrocene-chelating heteroscorpionate, [Li(THF)(2)][fc(PPh2)(BH[(3,5-Me)(2)pz](2))] ((fc(P,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)(2)pz](2))] (pz = pyrazole), was isolated and characterized. Compound (fc(P,B))Li(THF)(2) allowed the synthesis of the corresponding nickel and zinc complexes, (fc(P,B))NiCl, (fc(P,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 (fc(P,B))NiCl, (fc(P,B))NiMe, (fc(P,B))ZnCl, and (fc(P,B))ZnMe was studied by cyclic voltammetry and supported by density functional theory calculations.