A new polymorph of Ba(AsO3OH): Synthesis, crystal structure and vibrational spectra

Autor(en)
Tamara Đorđević, Ljiljana Karanovic
Abstrakt

A new monoclinic polymorph of Ba(AsO3OH) was synthesized under hydrothermal conditions. Itrepresents a previously unknown structure type. Its crystal structure was determined from a racemictwin using single-crystal X-ray diffraction data collected at 120 and 293 K [space group P21,a¼7.2149(14)/7.2370(2), b¼7.7028(15)/7.7133(2), c¼21.7385(43)/21.8079(5) A° , b¼95.95(3)/96.073(1)1,V¼1201.6(4)/1210.51(5) °A3, Z¼12]. The crystal structure of P21-Ba(AsO3OH) has a layered characterand is built up of four types of regularly alternating layers parallel to (0 0 1). Every AsO3OH tetrahedronis chelating to two Ba atoms and bridged by another two Ba atoms. Each OH group acts as hydrogenbond donor toward the oxygen atoms positioned in the same or adjacent layers. Although the H atomscould not be located, no ambiguities are present in the hydrogen-bonding scheme. Single-crystalvibrational spectroscopy (FTIR and Raman) was used to describe the vibrational behavior of thehydrogen bond system; particularly the spectroscopic manifestation of the very short and shorthydrogen bonds (2.462(7)-2.575(7) A° ). In order to complement spectroscopic data on protonatedorthoarsenates, infrared spectra of triclinic F1. -Sr(AsO3OH) and the orthorhombic variety of Pbca-Ba(AsO3OH) were recorded and discussed. Furthermore, structural features of other alkaline earthhydrogen arsenates are discussed.

Organisation(en)
Institut für Mineralogie und Kristallographie
Externe Organisation(en)
University of Belgrade
Journal
Journal of Solid State Chemistry
Band
183
Seiten
2835-2844
Anzahl der Seiten
10
ISSN
0022-4596
Publikationsdatum
2010
Peer-reviewed
Ja
ÖFOS 2012
105113 Kristallographie, 1030 Physik, Astronomie
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/ffd0bc70-597a-4b42-83b3-14d2e5eeb4e1