CRYSTAL-STRUCTURE OF KPBFEF6.H2O

The crystal structure of the new hydrated fluoride KPbFeF6. H2O is studied by using a single crystal obtained by hydrothermal synthesis in HF solution. The cell is triclinic ( P 1BAR, Z = 2 ) with a = 5.955(1) angstrom, b = 6.125(1) angstrom, c = 8.694(2) angstrom, alpha = 86.35(1)-degrees, beta = 82.63(1)-degrees and gamma = 89.62(1)-degrees. The structure was solved from 2565 X ray reflections and the final reliability factors are R = 0.029 and R(w) = 0.028. The structure is described in term of (FeF6) octahedra linked by Pb2+ ions building a three-dimensional corner-sharing structure. Including two water molecules, the Pb2+ is eight-coordinated by a bicapped trigonal prism.