Electron Paramagnetic Resonance Study of Cu2+ in K2Zn(ZrF6)2 · 6 H2O

An EPR study of Cu2+ ions in K2Zn(ZrF6) · 6 H2O in the temperature range 4.2 to 300 K at X and Q bands is carried out on single crystals and powders. The presence of the two conjugated Cu(H2O)62+ complexes is discovered and the angles between respective axes of the rhombic crystalline field are determined. The temperature dependence of the Cu2+ EPR spectrum tensor parameters is discussed in terms of dynamic Jahn‐Teller effect. The additional arguments in favour of the dynamic nature of the observed phenomena are given and the values of the energy splittings between three possible Jahn‐Teller configurations δ1,2 ≈︁ 280 cm−1, δ1,3 ⪆ 1000 cm−1 are obtained. The necessity of the “dynamic” approach to the study of “static” Jahn‐Teller EPR spectra of Cu(H2O)62+ complexes in similar low‐symmetry crystals is shown. Russian text ignored.