Hydrothermal and ionothermal synthesis of mineral-related arsenates in the system CdO-MO-As2O5 (M2+ = Mg, Co, Ni, Cu, Zn) and their crystal structures

Author(s)
Tamara Đorđević, Sabrina Stefanie Gerger, Ljiljana Karanovic
Abstract

During systematic research on the mineral-related arsenates in the system CdO-MO-As

2O

5-H

2O (M

2+ = Mg, Co, Ni, Cu, Zn), three new Cd-containing arsenates Cd

4.65Ni

0.35 (AsO

4)2(HAsO

4)

24H

2O (1), Cd

0.75Co

2.75 (H

0.5AsO

4)2(HAsO

4) (2) and Cd

1.25Zn

0.75 (HAsO

4)

22H

2O (3) have been synthesized under hydrothermal conditions, while the Zn-arsenate Zn

9 (AsO

4)

64H

2O (4) and again 2 have been prepared under ionothermal conditions using the ionic liquid 1-ethyl-3-methylimidazolium bromide, (C6H11N2)Br, as the solvent. Their crystal structures were determined using single-crystal X-ray diffraction data and refined to the reasonably low R-values: 1 - R

1 = 0.030; 2 - R

1 = 0.047; 3 - R

1 = 0.029; 6 - R

1 = 0.029. The compounds 1, 2 and 3 are structural analogues of three different arsenate mineral phases. Compound 4 was for the first time synthesized using ionic liquid as the solvent and the hydrogen atoms were found and refined. Infrared and Raman spectra were measured and evaluated in order to obtain further information on the anion groups and especially on the short hydrogen bonds. The OH stretching frequency is in good agreement with the observed O:::O distances. The different approaches in the synthesis of mineral-related arsenates, the temperature treatment as well as the role of added water in ionothermal synthesis are also discussed.

Organisation(s)
Department of Mineralogy and Crystallography
External organisation(s)
University of Belgrade
Journal
European Journal of Mineralogy: an international journal of mineralogy, geochemistry and related sciences
Volume
29
Pages
73-89
No. of pages
17
ISSN
0935-1221
DOI
https://doi.org/10.1127/ejm/2017/0029-2585
Publication date
10-2016
Peer reviewed
Yes
Austrian Fields of Science 2012
104026 Spectroscopy, 104017 Physical chemistry, 105113 Crystallography
Keywords
ASJC Scopus subject areas
Geochemistry and Petrology
Portal url
https://ucrisportal.univie.ac.at/en/publications/0708c128-9f8a-44f9-a3fe-833a1adc5462