![]() The decomposition starts at 130 ☌ in inert atmosphere with oxidation of a small part of urea (~ 1 molecule), which supports the heat demand of the transformation of the remaining urea into ammonia and biuret/isocyanate. The thermal decomposition of compound 1 was followed by TG-MS and DSC methods in oxidative and inert atmospheres as well. There are spectroscopically six kinds of urea and three kinds (2 + 1) of persulfate ions in compound 1, thus to distinguish the overlapping bands belonging to internal and external vibrational modes, deuteration of compound 1 and low-temperature Raman measurements were also carried out, and the bands belonging to the vibrational modes of urea and persulfate ions have been assigned. The two types of peroxydisulfate anions form different kinds and numbers of hydrogenīonds with the neighboring 3+ cations. ![]() Persulfate anions is stabilized by extended intramolecular (N–H⋯O = C) and intermolecular (N–H⋯O–S) hydrogen bonds. FeSO4 also turns into α-Fe2O3 and SO2 on further heating. FeSO4 formed in 27 and 75% at 420 and 490 ☌, respectively. Above 400 ☌ (at isotherm heating), however, the reduction of iron(III) centers was also observed. NH4Fe(SO4)2 transforms into Fe2(SO4)3, N2,H2O, and SO2 at 400 ☌, thus the precursor of α-Fe2O3 is Fe2(SO4)3. Theĭecomposition pathway of NH4Fe(SO4)2, however, depends on the experimental conditions. (NH4)3Fe(SO4)3 via NH4Fe(SO4)2 formation resulted in α-Fe2O3. In inert atmosphere, some iron(II) compound also formed. The main solid product proved to be (NH4)3Fe(SO4)3 in air. Of decomposition is the oxidation of ammonia into N2 along with the formation of SO2 The two types of peroxydisulfate anions form different kinds and numbers of hydrogen bonds with the neighboring 3+ cations. The octahedral arrangement of the complex cation and its packing with two crystallographically different ![]() Six crystallographically different urea ligands coordinate via their oxygen in a propeller-like arrangement to iron(III) forming a distorted octahedral complex cation. The todorokite-like intermediate prepared from compound 1 under N2 at 115 ∘C resulted in a 54 times faster degradation of Congo red, which is a great deal faster than the same todorokite-like phase that formed from compound 2 under N2.Īnhydrous hexakis(urea-O)iron(III)]peroxydisulfate (2(S2O8)3 (compound 1), and its deuterated form were prepared and characterized with single-crystal X-ray diffraction and spectroscopic (IR, Raman, UV, and Mössbauer) methods. The decomposition rate of the dye was found to be nine times faster than in the presence of the tetragonal CoMn2O4 spinel prepared in the solid-phase decomposition of compound 2. The Co1.5Mn1.5O4 prepared from compound 1 at 500 ∘C during the solid-phase decomposition catalyzes the degradation of Congo red with UV light. The heating of the decomposition product of compounds 1 and 2 that formed under refluxing toluene (a mixture with an atomic ratio of Co:Mn = 1:1 and 1:2) and after aqueous leaching ((NH4)4Co2Mn6O12, 1:3 Co:Mn atomic ratio in both cases) at 500 ∘C resulted in tetragonal Co0.75Mn2.25O4 spinels. The heat treatment products of compounds 1 and (MnO4)2 (2) synthesized previously at 500 ∘C were a cubic and a tetragonal spinel with Co1.5Mn1.5O4 and CoMn2O4 composition, respectively. which contains a todorokite-like manganese oxide network (MnII4MnIII2O1210−). The temperature-limited thermal decomposition of compound 1 under the temperature of boiling toluene (110 ∘C) resulted in the formation of (NH4)4Co2Mn6O12. The 3D−hydrogen bond network includes N–HO–Mn and N–HCl interactions responsible for solid-phase redox reactions between the permanganate anions and ammonia ligands. We synthesized and characterized (IR, Raman, UV, SXRD) hexaamminecobalt(III) dichloride permanganate, Cl2(MnO4) (compound 1) as the precursor of Co–Mn–spinel composites with atomic ratios of Co:Mn = 1:1 and 1:3.
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