title: Octahedral-tetrahedral framework structures of InAsO4.H2O and PbIn(AsO4)(AsO3OH).
abstract: Indium arsenate(V) monohydrate, InAsO4.H2O, (I), crystallizes in the structure type of MnMoO4.H2O. The structure is built of In2O8(H2O)2 dimers (mean In-O=2.150 A) corner-linked to slightly distorted AsO4 tetrahedra (mean As-O=1.686 A). The linkage results in a three-dimensional framework, with small voids into which the apical water ligand of the InO5(H2O) octahedron points. The hydrogen bonds in (I) are of medium strength. Lead(II) indium arsenate(V) hydrogen arsenate(V), PbIn(AsO4)(AsO3OH), (II), represents the first reported lead indium arsenate. It is characterized by a framework structure of InO6 octahedra corner-linked to AsO4 and AsO3OH tetrahedra. The resulting voids are occupied by Pb2O10(OH)2 dimers built of two edge-sharing highly distorted PbO6(OH) polyhedra (mean Pb-O=2.623 A). The compound is isotypic with PbFe(III)(AsO4)(AsO3OH). The average In-O bond length in (II) is 2.157 A. In both arsenates, all atoms are in general positions.
authors.affiliation: Universität Wien, Institut für Mineralogie und Kristallographie, Geozentrum, Althanstrasse 14, A-1090 Wien, Austria. uwe.kolitsch@univie.ac.at
authors.forename: Uwe
authors.initials: U
authors.lastname: Kolitsch
authors.forename: Karolina
authors.initials: K
authors.lastname: Schwendtner