Solid-Phase Quasi-Intramolecular Redox Reaction of [Ag(NH₃)₂]MnO₄: An Easy Way to Prepare Pure AgMnO₂

Two monoclinic polymorphs of [Ag(NH3)2]MnO4 containing a unique coordination mode permanganate ions were prepared, and the high-temperature polymorph was used as precursor to synthesize pure AgMnO2. The hydrogen bonds between atoms ammonia detected by IR spectroscopy single-crystal X-ray diffraction. Under thermal decomposition, these induced solid-phase quasi-intramolecular redox reaction [Ag(NH3)2]+ cation MnO4– anion even before losing ligand or oxygen atom. decomposed into finely dispersed elementary silver, amorphous MnOx compounds, H2O, N2 NO gases. Annealing primary decomposition product at 573 K, metallic silver reacted with manganese oxides resulted in formation oxides, which started crystallize only 773 K completely transformed AgMnO2 873 K.