Evidence of quasi-intramolecular redox reactions during thermal decomposition of ammonium hydroxodisulfitoferriate(III), (NH₄)₂[Fe(OH) (SO₃)₂]•H₂O

Autor(en)

Tünde Kocsis, József Magyari, István E. Sajó, Tibor Pasinszki, Zlotán Homonnay, Imre M. Szilágyi, Attila Farkas, Zoltán May, Herta Silvia Effenberger, Sándor Szakáll, Rajendra P. Pawar, László Kótai

Abstrakt

Synthesis of ammonium hydroxodisulfitoferriate(III) , (diammonium catena- {bis(µ2- sulfito- O, O) - µ2- hydroxo- 2O} ferrate(III) monohydrate) (NH4) 2[Fe(OH) (SO3) 2] ·H2O (compd. 1) and its thermal behavior is reported. The compd. is stable in air. Its thermal decompn. proceeds without the expected quasi- intramol. oxidn. of sulfite ion with ferric ions. The disproportionation reaction of the ammonium sulfite, formed from the evolved NH3, SO2 and H2O in the main decompn. stage of 1, results in the formation of ammonium sulfate and ammonium sulfide. The ammonium sulfide is unstable at the decompn. temp. of 1 (150 °C) and transforms into NH3 and H2S which immediately forms elementary sulfur by reaction with SO2. The formation and decompn. of other intermediate compds. like (NH4) 2SnOx (n = 2, x = 3 and n = 3, x = 6) results in the same decompn. products (S, SO2 and NH3) . Two basic iron sulfates, formed in different ratios during synthesizing expts. performed under N2 or in the presence of air, have been detected as solid intermediates which contain ammonium ions. The final decompn. product was proved to be a- Fe2O3 (mineral name hematite).

Organisation(en)

Institut für Mineralogie und Kristallographie

Externe Organisation(en)

Magyar Tudományos Akadémia, University of Novi Sad (UNS), University of Pécs, Eötvös Loránd University Budapest, Budapest University of Technology and Economics, University of Miskolc, Deogiri College

Journal

Journal of Thermal Analysis and Calorimetry: an international forum for thermal studies

Band

132

Seiten

493-502

Anzahl der Seiten

10

ISSN

1388-6150

DOI

https://doi.org/10.1007/s10973-017-6901-4

Publikationsdatum

04-2018

Peer-reviewed

Ja

ÖFOS 2012

104003 Anorganische Chemie, 104026 Spektroskopie, 104017 Physikalische Chemie, 105113 Kristallographie

Schlagwörter

ASJC Scopus Sachgebiete

Condensed Matter Physics, Physical and Theoretical Chemistry

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/f83f5eea-89cb-4f95-9ebc-3831d2f1af5b