title: Oxonium ions substituting cesium ions in the structure of the new high-pressure borate HP-Cs(1-x)(H(3)O)(x)B(3)O(5) (x=0.5-0.7).
abstract: The new high-pressure borate HP-Cs1-x (H3 O)x B3 O5 (x=0.5-0.7) was synthesized under high-pressure/high-temperature conditions of 6 GPa/900 °C in a Walker-type multianvil apparatus. The compound crystallizes in the monoclinic space group C2/c (Z=8) with the parameters a=1000.6(2), b=887.8(2), c=926.3(2) pm, β=103.1(1)°, V=0.8016(3) nm(3) , R1=0.0452, and wR2=0.0721 (all data). The boron-oxygen network is analogous to those of the compounds HP-MB3 O5 , (M=K, Rb) and exhibits all three structural motifs of borates-BO3 groups, corner-sharing BO4 tetrahedra, and edge-sharing BO4 tetrahedra-at the same time. Channels inside the boron-oxygen framework contain the cesium and oxonium ions, which are disordered on a specific site. Estimating the amount of hydrogen by solid-state NMR spectroscopy and X-ray diffraction led to the composition HP-Cs1-x (H3 O)x B3 O5 (x=0.5-0.7), which implies a nonzero phase width.
authors.affiliation: Institut für Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Universität Innsbruck, Innrain 80-82, 6020 Innsbruck (Austria).
authors.forename: Gerhard
authors.initials: G
authors.lastname: Sohr
authors.forename: Stephanie C
authors.initials: SC
authors.lastname: Neumair
authors.forename: Gunter
authors.initials: G
authors.lastname: Heymann
authors.forename: Klaus
authors.initials: K
authors.lastname: Wurst
authors.forename: Jörn
authors.initials: J
authors.lastname: Schmedt auf der Günne
authors.forename: Hubert
authors.initials: H
authors.lastname: Huppertz
keywords: borates; cesium; high-pressure chemistry; solid-state structures; structure elucidation