Investigation of low-hydrated metal(II) nitrates

Author(s)
Manfred Wildner, Gerald Giester, Christian Lengauer, Josef Zemann
Abstract

Crystals of Zn(NO3)2×H2O and Mn(NO3)2×2 H2O were synthesized by heating melts of the respective penta- or hexahydrates. Single crystal X-ray diffraction of the two highly hygroscopic phases reveals new sheet-structure types: Zn(NO3)2×H2O [Pbca, a = 9.722(1), b = 5.865(1), c = 17.799(3) Å (120 K), Z = 8, R1 = 0.025]; Mn(NO3)2×2 H2O [P212121, a = 5.921(1), b = 8.835(1), c = 22.882(3) Å (120 K), Z = 8, R1 = 0.020]. Zn(NO3)2×H2O is built of only one kind of complicated, corrugated sheets held together by hydrogen bonds, while Mn(NO3)2×2 H2O is built of alternating sheets with Mn in 6- and 7-fold coordination, respectively, again interconnected by hydrogen bonds. While in Zn(NO3)2×H2O the hydrogen bond system is quite clear-cut, this is not the case in Mn(NO3)2×2 H2O. Contrary to expectation, the thermal expansion is not clearly largest perpendicular to the sheets in both compounds.In the well known structures of the nitrate dihydrates of Mg, Co and Ni new refinements allowed to locate the hydrogen atoms.Together with Mn(II) nitrate monohydrate and the dihydrates of Mg, Co, Ni, Zn and Cd the two new nitrates form an interesting group of sheet structures.

Organisation(s)
Department of Mineralogy and Crystallography
Journal
Zeitschrift für Kristallographie - Crystalline Materials
Volume
227
Pages
129-140
No. of pages
12
ISSN
2194-4946
DOI
https://doi.org/10.1524/zkri.2012.1463
Publication date
2012
Peer reviewed
Yes
Austrian Fields of Science 2012
105113 Crystallography
Portal url
https://ucrisportal.univie.ac.at/en/publications/f2cd0ea4-ed7a-49c1-a189-635e87e126f9