title: Two bismuth oxalate hydrates and revision of their chemical formulae.
abstract: The crystal structures of two bismuth(III) oxalate hydrates, previously described as 'Bi(2)(C(2)O(4))(3).H(2)C(2)O(4)' and 'Bi(2)(C(2)O(4))(3).7H(2)O', were solved and refined from single-crystal X-ray diffraction data. The results led to the revised chemical formulae Bi(2)(C(2)O(4))(3).6H(2)O and Bi(2)(C(2)O(4))(3).8H(2)O, respectively. Both dibismuth(III) trioxalate hexahydrate (tetraaquatri-micro-oxalato-dibismuth(III) dihydrate, [[Bi(2)(C(2)O(4))(3)(H(2)O)(4)].2H(2)O](n)) and dibismuth(III) trioxalate octahydrate (tetraaquatri-micro-oxalato-dibismuth(III) tetrahydrate [[Bi(2)(C(2)O(4))(3)(H(2)O)(4)].4H(2)O](n)) are characterized by a three-dimensional network of Bi atoms connected by tetradentate oxalate groups. All ligand and 'free' water molecules are located in channels and voids. The mean Bi-O bond lengths are approximately 2.51 A. The lone electron pairs on all Bi(3+) cations are stereochemically inactive.
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