Dynamic Behavior of the Jahn-Teller Distorted Cu(H2O)62+ Ion in Cu2+ Doped Cs2[Zn(H2O)6](ZrF6)2 and the Crystal Structure of the Host Lattice

The temperature dependence of the X- and Q-band EPR spectra of Cs 2[Zn(H 2O) 6](ZrF 6) 2 containing 1% Cu 2+ is reported. All three molecular g-values vary with temperature, and their behavior is interpreted using a model in which the potential surface of the Jahn-Teller distorted Cu(H 2O) 6 2+ ion is perturbed by an orthorhombic "strain" induced by interactions with the surrounding lattice. The strain parameters are significantly smaller than those reported previously for the Cu(H 2O) 6 2+ ion in similar lattices. The temperature dependence of the two higher g-values suggests that in the present compound the lattice interactions change slightly with temperature. The crystal structure of the Cs 2[Zn(H 2O) 6](ZrF 6) 2 host is reported, and the geometry of the Zn(H 2O) 6 2+ ion is correlated with lattice strain parameters derived from the EPR spectrum of the guest Cu 2+ complex.