Dimers of Ag2+ Ions – Synthesis and Characterization of the Quaternary Silver Fluoride Ag2ZnZr2F14 with [Ag2F7]3– Units


  • Dedicated to Professor Hanskarl Müller-Buschbaum on the Occasion of His 80th Birthday


Deep blue-violet colored powder samples of Ag2ZnZr2F14 were synthesized by heating Zn(NO3)2·4H2O, Ag and ZrOCl2·8H2O at 300 °C under fluorine atmosphere. The crystal structure of Ag2ZnZr2F14 was refined from X-ray powder diffraction data using the Rietveld method (C2/m, a = 9.0206(1) Å, b = 6.6373(1) Å, c = 9.0563(1) Å, β = 90.44(1)°, Z = 2). The structure is derived from the isotypic Ag3Zr2F14 by replacing only one of the two crystallographically different Ag2+ ions with Zn2+ ions, thus leading to discrete Ag2F7 dimers. These dimers are connected via nearly linear Ag–F···F–Ag bridges with short F···F distances of 2.33 Å to form two-legged ladders. Magnetic susceptibility measurements and density functional calculations show that the two Ag2+ ions in each Ag2F7 dimer are strongly coupled antiferromagnetically.