Single crystal E.P.R. Spectra of copper(II) and manganese(II) doped ammonium tetrafluorozincate(II) dihydrate

A detailed single crystal E.P.R. study of copper(II) in a low symmetry environment provided by the hexacoordinate complex (NH4)2ZnF4.2H20 is reported. Only two fluorines show hyperfine interaction. The analysis shows that the symmetry of the complex is Dth similar to the corresponding ferromagnetic chloro and bromo complexes, viz. M2CuX4.2H20 where M=NH4+, K+, Rb+, Cs+ and X = Cl, Br. The effect of a low symmetry environment was further tested by doping Mn2+ in the same host lattice. There is a large D tensor with a small E showing departure from axial symmetry. There is excellent agreement between the experimental and theoretical line positions computed using third order perturbation theory. The determination of the orientation of the magnetic tensor components with respect to the molecular axes and metal and ligand hyperfine coupling parameters obtained by extensive computer simulation reveals the bonding properties of these complexes. © 1983 Taylor and Francis Group, LLC.