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Solid-Phase Quasi-Intramolecular Redox Reaction of [Ag(NH 3 ) 2 ]MnO 4 : An Easy Way to Prepare Pure AgMnO 2 .

Authors :
Fogaca LA
Kováts É
Németh G
Kamarás K
Béres KA
Németh P
Petruševski V
Bereczki L
Holló BB
Sajó IE
Klébert S
Farkas A
Szilágyi IM
Kótai L
Source :
Inorganic chemistry [Inorg Chem] 2021 Mar 15; Vol. 60 (6), pp. 3749-3760. Date of Electronic Publication: 2021 Mar 01.
Publication Year :
2021

Abstract

Two monoclinic polymorphs of [Ag(NH <subscript>3</subscript> ) <subscript>2</subscript> ]MnO <subscript>4</subscript> containing a unique coordination mode of permanganate ions were prepared, and the high-temperature polymorph was used as a precursor to synthesize pure AgMnO <subscript>2</subscript> . The hydrogen bonds between the permanganate ions and the hydrogen atoms of ammonia were detected by IR spectroscopy and single-crystal X-ray diffraction. Under thermal decomposition, these hydrogen bonds induced a solid-phase quasi-intramolecular redox reaction between the [Ag(NH <subscript>3</subscript> ) <subscript>2</subscript> ] <superscript>+</superscript> cation and MnO <subscript>4</subscript> <superscript> - </superscript> anion even before losing the ammonia ligand or permanganate oxygen atom. The polymorphs decomposed into finely dispersed elementary silver, amorphous MnO <subscript> x </subscript> compounds, and H <subscript>2</subscript> O, N <subscript>2</subscript> and NO gases. Annealing the primary decomposition product at 573 K, the metallic silver reacted with the manganese oxides and resulted in the formation of amorphous silver manganese oxides, which started to crystallize only at 773 K and completely transformed into AgMnO <subscript>2</subscript> at 873 K.

Details

Language :
English
ISSN :
1520-510X
Volume :
60
Issue :
6
Database :
MEDLINE
Journal :
Inorganic chemistry
Publication Type :
Academic Journal
Accession number :
33647206
Full Text :
https://doi.org/10.1021/acs.inorgchem.0c03498