EPR of Cu(II)-doped hexakis(pyrazole) complexes of Zn(II) and Cd(II): coexistence of isotropic and anisotropic spectra

Single-crystal and powder EPR spectral studies of Cu(II)-doped Zn(pz) 6 (BF 4 ) 2 and Cd(pz) 6 (BF 4 ) 2 show that isotropic and anisotropic spectra coexist at 300K. For Cu(II) doped Zn(pz) 6 (BF 4 ) 2 , g iso = 2.1303 and the corresponding anisotropic signal is characterized by g∥ = 2.2616 and g⊥ = 2.0662. By studying the temperature dependence of the intensities of the EPR lines, the isotropic signal is attributed to the vibrational excited states. The anisotropic signals arise from the three tetragonally elongated octahedra corresponding to static Jahn-Teller distortion. Powder spectra have been computer simulated to obtain spin Hamiltonian parameters.